1 /* Functions related to building classes and their related objects.
2 Copyright (C) 1987-2013 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com)
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21
22 /* High-level class interface. */
23
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "tree.h"
29 #include "cp-tree.h"
30 #include "flags.h"
31 #include "toplev.h"
32 #include "target.h"
33 #include "convert.h"
34 #include "cgraph.h"
35 #include "dumpfile.h"
36 #include "splay-tree.h"
37 #include "pointer-set.h"
38 #include "hash-table.h"
39
40 /* The number of nested classes being processed. If we are not in the
41 scope of any class, this is zero. */
42
43 int current_class_depth;
44
45 /* In order to deal with nested classes, we keep a stack of classes.
46 The topmost entry is the innermost class, and is the entry at index
47 CURRENT_CLASS_DEPTH */
48
49 typedef struct class_stack_node {
50 /* The name of the class. */
51 tree name;
52
53 /* The _TYPE node for the class. */
54 tree type;
55
56 /* The access specifier pending for new declarations in the scope of
57 this class. */
58 tree access;
59
60 /* If were defining TYPE, the names used in this class. */
61 splay_tree names_used;
62
63 /* Nonzero if this class is no longer open, because of a call to
64 push_to_top_level. */
65 size_t hidden;
66 }* class_stack_node_t;
67
68 typedef struct vtbl_init_data_s
69 {
70 /* The base for which we're building initializers. */
71 tree binfo;
72 /* The type of the most-derived type. */
73 tree derived;
74 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
75 unless ctor_vtbl_p is true. */
76 tree rtti_binfo;
77 /* The negative-index vtable initializers built up so far. These
78 are in order from least negative index to most negative index. */
79 vec<constructor_elt, va_gc> *inits;
80 /* The binfo for the virtual base for which we're building
81 vcall offset initializers. */
82 tree vbase;
83 /* The functions in vbase for which we have already provided vcall
84 offsets. */
85 vec<tree, va_gc> *fns;
86 /* The vtable index of the next vcall or vbase offset. */
87 tree index;
88 /* Nonzero if we are building the initializer for the primary
89 vtable. */
90 int primary_vtbl_p;
91 /* Nonzero if we are building the initializer for a construction
92 vtable. */
93 int ctor_vtbl_p;
94 /* True when adding vcall offset entries to the vtable. False when
95 merely computing the indices. */
96 bool generate_vcall_entries;
97 } vtbl_init_data;
98
99 /* The type of a function passed to walk_subobject_offsets. */
100 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
101
102 /* The stack itself. This is a dynamically resized array. The
103 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
104 static int current_class_stack_size;
105 static class_stack_node_t current_class_stack;
106
107 /* The size of the largest empty class seen in this translation unit. */
108 static GTY (()) tree sizeof_biggest_empty_class;
109
110 /* An array of all local classes present in this translation unit, in
111 declaration order. */
112 vec<tree, va_gc> *local_classes;
113
114 static tree get_vfield_name (tree);
115 static void finish_struct_anon (tree);
116 static tree get_vtable_name (tree);
117 static tree get_basefndecls (tree, tree);
118 static int build_primary_vtable (tree, tree);
119 static int build_secondary_vtable (tree);
120 static void finish_vtbls (tree);
121 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
122 static void finish_struct_bits (tree);
123 static int alter_access (tree, tree, tree);
124 static void handle_using_decl (tree, tree);
125 static tree dfs_modify_vtables (tree, void *);
126 static tree modify_all_vtables (tree, tree);
127 static void determine_primary_bases (tree);
128 static void finish_struct_methods (tree);
129 static void maybe_warn_about_overly_private_class (tree);
130 static int method_name_cmp (const void *, const void *);
131 static int resort_method_name_cmp (const void *, const void *);
132 static void add_implicitly_declared_members (tree, tree*, int, int);
133 static tree fixed_type_or_null (tree, int *, int *);
134 static tree build_simple_base_path (tree expr, tree binfo);
135 static tree build_vtbl_ref_1 (tree, tree);
136 static void build_vtbl_initializer (tree, tree, tree, tree, int *,
137 vec<constructor_elt, va_gc> **);
138 static int count_fields (tree);
139 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
140 static void insert_into_classtype_sorted_fields (tree, tree, int);
141 static bool check_bitfield_decl (tree);
142 static void check_field_decl (tree, tree, int *, int *, int *);
143 static void check_field_decls (tree, tree *, int *, int *);
144 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
145 static void build_base_fields (record_layout_info, splay_tree, tree *);
146 static void check_methods (tree);
147 static void remove_zero_width_bit_fields (tree);
148 static void check_bases (tree, int *, int *);
149 static void check_bases_and_members (tree);
150 static tree create_vtable_ptr (tree, tree *);
151 static void include_empty_classes (record_layout_info);
152 static void layout_class_type (tree, tree *);
153 static void propagate_binfo_offsets (tree, tree);
154 static void layout_virtual_bases (record_layout_info, splay_tree);
155 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
156 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
157 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
158 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
159 static void add_vcall_offset (tree, tree, vtbl_init_data *);
160 static void layout_vtable_decl (tree, int);
161 static tree dfs_find_final_overrider_pre (tree, void *);
162 static tree dfs_find_final_overrider_post (tree, void *);
163 static tree find_final_overrider (tree, tree, tree);
164 static int make_new_vtable (tree, tree);
165 static tree get_primary_binfo (tree);
166 static int maybe_indent_hierarchy (FILE *, int, int);
167 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
168 static void dump_class_hierarchy (tree);
169 static void dump_class_hierarchy_1 (FILE *, int, tree);
170 static void dump_array (FILE *, tree);
171 static void dump_vtable (tree, tree, tree);
172 static void dump_vtt (tree, tree);
173 static void dump_thunk (FILE *, int, tree);
174 static tree build_vtable (tree, tree, tree);
175 static void initialize_vtable (tree, vec<constructor_elt, va_gc> *);
176 static void layout_nonempty_base_or_field (record_layout_info,
177 tree, tree, splay_tree);
178 static tree end_of_class (tree, int);
179 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree);
180 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree,
181 vec<constructor_elt, va_gc> **);
182 static void dfs_accumulate_vtbl_inits (tree, tree, tree, tree, tree,
183 vec<constructor_elt, va_gc> **);
184 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
185 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
186 static void clone_constructors_and_destructors (tree);
187 static tree build_clone (tree, tree);
188 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
189 static void build_ctor_vtbl_group (tree, tree);
190 static void build_vtt (tree);
191 static tree binfo_ctor_vtable (tree);
192 static void build_vtt_inits (tree, tree, vec<constructor_elt, va_gc> **,
193 tree *);
194 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
195 static tree dfs_fixup_binfo_vtbls (tree, void *);
196 static int record_subobject_offset (tree, tree, splay_tree);
197 static int check_subobject_offset (tree, tree, splay_tree);
198 static int walk_subobject_offsets (tree, subobject_offset_fn,
199 tree, splay_tree, tree, int);
200 static void record_subobject_offsets (tree, tree, splay_tree, bool);
201 static int layout_conflict_p (tree, tree, splay_tree, int);
202 static int splay_tree_compare_integer_csts (splay_tree_key k1,
203 splay_tree_key k2);
204 static void warn_about_ambiguous_bases (tree);
205 static bool type_requires_array_cookie (tree);
206 static bool contains_empty_class_p (tree);
207 static bool base_derived_from (tree, tree);
208 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
209 static tree end_of_base (tree);
210 static tree get_vcall_index (tree, tree);
211
212 /* Variables shared between class.c and call.c. */
213
214 int n_vtables = 0;
215 int n_vtable_entries = 0;
216 int n_vtable_searches = 0;
217 int n_vtable_elems = 0;
218 int n_convert_harshness = 0;
219 int n_compute_conversion_costs = 0;
220 int n_inner_fields_searched = 0;
221
222 /* Convert to or from a base subobject. EXPR is an expression of type
223 `A' or `A*', an expression of type `B' or `B*' is returned. To
224 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
225 the B base instance within A. To convert base A to derived B, CODE
226 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
227 In this latter case, A must not be a morally virtual base of B.
228 NONNULL is true if EXPR is known to be non-NULL (this is only
229 needed when EXPR is of pointer type). CV qualifiers are preserved
230 from EXPR. */
231
232 tree
build_base_path(enum tree_code code,tree expr,tree binfo,int nonnull,tsubst_flags_t complain)233 build_base_path (enum tree_code code,
234 tree expr,
235 tree binfo,
236 int nonnull,
237 tsubst_flags_t complain)
238 {
239 tree v_binfo = NULL_TREE;
240 tree d_binfo = NULL_TREE;
241 tree probe;
242 tree offset;
243 tree target_type;
244 tree null_test = NULL;
245 tree ptr_target_type;
246 int fixed_type_p;
247 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
248 bool has_empty = false;
249 bool virtual_access;
250
251 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
252 return error_mark_node;
253
254 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
255 {
256 d_binfo = probe;
257 if (is_empty_class (BINFO_TYPE (probe)))
258 has_empty = true;
259 if (!v_binfo && BINFO_VIRTUAL_P (probe))
260 v_binfo = probe;
261 }
262
263 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
264 if (want_pointer)
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
266
267 if (code == PLUS_EXPR
268 && !SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe))
269 {
270 /* This can happen when adjust_result_of_qualified_name_lookup can't
271 find a unique base binfo in a call to a member function. We
272 couldn't give the diagnostic then since we might have been calling
273 a static member function, so we do it now. */
274 if (complain & tf_error)
275 {
276 tree base = lookup_base (probe, BINFO_TYPE (d_binfo),
277 ba_unique, NULL, complain);
278 gcc_assert (base == error_mark_node);
279 }
280 return error_mark_node;
281 }
282
283 gcc_assert ((code == MINUS_EXPR
284 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
285 || code == PLUS_EXPR);
286
287 if (binfo == d_binfo)
288 /* Nothing to do. */
289 return expr;
290
291 if (code == MINUS_EXPR && v_binfo)
292 {
293 if (complain & tf_error)
294 error ("cannot convert from base %qT to derived type %qT via "
295 "virtual base %qT", BINFO_TYPE (binfo), BINFO_TYPE (d_binfo),
296 BINFO_TYPE (v_binfo));
297 return error_mark_node;
298 }
299
300 if (!want_pointer)
301 /* This must happen before the call to save_expr. */
302 expr = cp_build_addr_expr (expr, complain);
303 else
304 expr = mark_rvalue_use (expr);
305
306 offset = BINFO_OFFSET (binfo);
307 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
308 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
309 /* TARGET_TYPE has been extracted from BINFO, and, is therefore always
310 cv-unqualified. Extract the cv-qualifiers from EXPR so that the
311 expression returned matches the input. */
312 target_type = cp_build_qualified_type
313 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
314 ptr_target_type = build_pointer_type (target_type);
315
316 /* Do we need to look in the vtable for the real offset? */
317 virtual_access = (v_binfo && fixed_type_p <= 0);
318
319 /* Don't bother with the calculations inside sizeof; they'll ICE if the
320 source type is incomplete and the pointer value doesn't matter. In a
321 template (even in fold_non_dependent_expr), we don't have vtables set
322 up properly yet, and the value doesn't matter there either; we're just
323 interested in the result of overload resolution. */
324 if (cp_unevaluated_operand != 0
325 || in_template_function ())
326 {
327 expr = build_nop (ptr_target_type, expr);
328 if (!want_pointer)
329 expr = build_indirect_ref (EXPR_LOCATION (expr), expr, RO_NULL);
330 return expr;
331 }
332
333 /* If we're in an NSDMI, we don't have the full constructor context yet
334 that we need for converting to a virtual base, so just build a stub
335 CONVERT_EXPR and expand it later in bot_replace. */
336 if (virtual_access && fixed_type_p < 0
337 && current_scope () != current_function_decl)
338 {
339 expr = build1 (CONVERT_EXPR, ptr_target_type, expr);
340 CONVERT_EXPR_VBASE_PATH (expr) = true;
341 if (!want_pointer)
342 expr = build_indirect_ref (EXPR_LOCATION (expr), expr, RO_NULL);
343 return expr;
344 }
345
346 /* Do we need to check for a null pointer? */
347 if (want_pointer && !nonnull)
348 {
349 /* If we know the conversion will not actually change the value
350 of EXPR, then we can avoid testing the expression for NULL.
351 We have to avoid generating a COMPONENT_REF for a base class
352 field, because other parts of the compiler know that such
353 expressions are always non-NULL. */
354 if (!virtual_access && integer_zerop (offset))
355 return build_nop (ptr_target_type, expr);
356 null_test = error_mark_node;
357 }
358
359 /* Protect against multiple evaluation if necessary. */
360 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
361 expr = save_expr (expr);
362
363 /* Now that we've saved expr, build the real null test. */
364 if (null_test)
365 {
366 tree zero = cp_convert (TREE_TYPE (expr), nullptr_node, complain);
367 null_test = fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
368 expr, zero);
369 }
370
371 /* If this is a simple base reference, express it as a COMPONENT_REF. */
372 if (code == PLUS_EXPR && !virtual_access
373 /* We don't build base fields for empty bases, and they aren't very
374 interesting to the optimizers anyway. */
375 && !has_empty)
376 {
377 expr = cp_build_indirect_ref (expr, RO_NULL, complain);
378 expr = build_simple_base_path (expr, binfo);
379 if (want_pointer)
380 expr = build_address (expr);
381 target_type = TREE_TYPE (expr);
382 goto out;
383 }
384
385 if (virtual_access)
386 {
387 /* Going via virtual base V_BINFO. We need the static offset
388 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
389 V_BINFO. That offset is an entry in D_BINFO's vtable. */
390 tree v_offset;
391
392 if (fixed_type_p < 0 && in_base_initializer)
393 {
394 /* In a base member initializer, we cannot rely on the
395 vtable being set up. We have to indirect via the
396 vtt_parm. */
397 tree t;
398
399 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
400 t = build_pointer_type (t);
401 v_offset = convert (t, current_vtt_parm);
402 v_offset = cp_build_indirect_ref (v_offset, RO_NULL, complain);
403 }
404 else
405 v_offset = build_vfield_ref (cp_build_indirect_ref (expr, RO_NULL,
406 complain),
407 TREE_TYPE (TREE_TYPE (expr)));
408
409 v_offset = fold_build_pointer_plus (v_offset, BINFO_VPTR_FIELD (v_binfo));
410 v_offset = build1 (NOP_EXPR,
411 build_pointer_type (ptrdiff_type_node),
412 v_offset);
413 v_offset = cp_build_indirect_ref (v_offset, RO_NULL, complain);
414 TREE_CONSTANT (v_offset) = 1;
415
416 offset = convert_to_integer (ptrdiff_type_node,
417 size_diffop_loc (input_location, offset,
418 BINFO_OFFSET (v_binfo)));
419
420 if (!integer_zerop (offset))
421 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
422
423 if (fixed_type_p < 0)
424 /* Negative fixed_type_p means this is a constructor or destructor;
425 virtual base layout is fixed in in-charge [cd]tors, but not in
426 base [cd]tors. */
427 offset = build3 (COND_EXPR, ptrdiff_type_node,
428 build2 (EQ_EXPR, boolean_type_node,
429 current_in_charge_parm, integer_zero_node),
430 v_offset,
431 convert_to_integer (ptrdiff_type_node,
432 BINFO_OFFSET (binfo)));
433 else
434 offset = v_offset;
435 }
436
437 if (want_pointer)
438 target_type = ptr_target_type;
439
440 expr = build1 (NOP_EXPR, ptr_target_type, expr);
441
442 if (!integer_zerop (offset))
443 {
444 offset = fold_convert (sizetype, offset);
445 if (code == MINUS_EXPR)
446 offset = fold_build1_loc (input_location, NEGATE_EXPR, sizetype, offset);
447 expr = fold_build_pointer_plus (expr, offset);
448 }
449 else
450 null_test = NULL;
451
452 if (!want_pointer)
453 expr = cp_build_indirect_ref (expr, RO_NULL, complain);
454
455 out:
456 if (null_test)
457 expr = fold_build3_loc (input_location, COND_EXPR, target_type, null_test, expr,
458 build_zero_cst (target_type));
459
460 return expr;
461 }
462
463 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
464 Perform a derived-to-base conversion by recursively building up a
465 sequence of COMPONENT_REFs to the appropriate base fields. */
466
467 static tree
build_simple_base_path(tree expr,tree binfo)468 build_simple_base_path (tree expr, tree binfo)
469 {
470 tree type = BINFO_TYPE (binfo);
471 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
472 tree field;
473
474 if (d_binfo == NULL_TREE)
475 {
476 tree temp;
477
478 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
479
480 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
481 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
482 an lvalue in the front end; only _DECLs and _REFs are lvalues
483 in the back end. */
484 temp = unary_complex_lvalue (ADDR_EXPR, expr);
485 if (temp)
486 expr = cp_build_indirect_ref (temp, RO_NULL, tf_warning_or_error);
487
488 return expr;
489 }
490
491 /* Recurse. */
492 expr = build_simple_base_path (expr, d_binfo);
493
494 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
495 field; field = DECL_CHAIN (field))
496 /* Is this the base field created by build_base_field? */
497 if (TREE_CODE (field) == FIELD_DECL
498 && DECL_FIELD_IS_BASE (field)
499 && TREE_TYPE (field) == type
500 /* If we're looking for a field in the most-derived class,
501 also check the field offset; we can have two base fields
502 of the same type if one is an indirect virtual base and one
503 is a direct non-virtual base. */
504 && (BINFO_INHERITANCE_CHAIN (d_binfo)
505 || tree_int_cst_equal (byte_position (field),
506 BINFO_OFFSET (binfo))))
507 {
508 /* We don't use build_class_member_access_expr here, as that
509 has unnecessary checks, and more importantly results in
510 recursive calls to dfs_walk_once. */
511 int type_quals = cp_type_quals (TREE_TYPE (expr));
512
513 expr = build3 (COMPONENT_REF,
514 cp_build_qualified_type (type, type_quals),
515 expr, field, NULL_TREE);
516 expr = fold_if_not_in_template (expr);
517
518 /* Mark the expression const or volatile, as appropriate.
519 Even though we've dealt with the type above, we still have
520 to mark the expression itself. */
521 if (type_quals & TYPE_QUAL_CONST)
522 TREE_READONLY (expr) = 1;
523 if (type_quals & TYPE_QUAL_VOLATILE)
524 TREE_THIS_VOLATILE (expr) = 1;
525
526 return expr;
527 }
528
529 /* Didn't find the base field?!? */
530 gcc_unreachable ();
531 }
532
533 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
534 type is a class type or a pointer to a class type. In the former
535 case, TYPE is also a class type; in the latter it is another
536 pointer type. If CHECK_ACCESS is true, an error message is emitted
537 if TYPE is inaccessible. If OBJECT has pointer type, the value is
538 assumed to be non-NULL. */
539
540 tree
convert_to_base(tree object,tree type,bool check_access,bool nonnull,tsubst_flags_t complain)541 convert_to_base (tree object, tree type, bool check_access, bool nonnull,
542 tsubst_flags_t complain)
543 {
544 tree binfo;
545 tree object_type;
546
547 if (TYPE_PTR_P (TREE_TYPE (object)))
548 {
549 object_type = TREE_TYPE (TREE_TYPE (object));
550 type = TREE_TYPE (type);
551 }
552 else
553 object_type = TREE_TYPE (object);
554
555 binfo = lookup_base (object_type, type, check_access ? ba_check : ba_unique,
556 NULL, complain);
557 if (!binfo || binfo == error_mark_node)
558 return error_mark_node;
559
560 return build_base_path (PLUS_EXPR, object, binfo, nonnull, complain);
561 }
562
563 /* EXPR is an expression with unqualified class type. BASE is a base
564 binfo of that class type. Returns EXPR, converted to the BASE
565 type. This function assumes that EXPR is the most derived class;
566 therefore virtual bases can be found at their static offsets. */
567
568 tree
convert_to_base_statically(tree expr,tree base)569 convert_to_base_statically (tree expr, tree base)
570 {
571 tree expr_type;
572
573 expr_type = TREE_TYPE (expr);
574 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
575 {
576 /* If this is a non-empty base, use a COMPONENT_REF. */
577 if (!is_empty_class (BINFO_TYPE (base)))
578 return build_simple_base_path (expr, base);
579
580 /* We use fold_build2 and fold_convert below to simplify the trees
581 provided to the optimizers. It is not safe to call these functions
582 when processing a template because they do not handle C++-specific
583 trees. */
584 gcc_assert (!processing_template_decl);
585 expr = cp_build_addr_expr (expr, tf_warning_or_error);
586 if (!integer_zerop (BINFO_OFFSET (base)))
587 expr = fold_build_pointer_plus_loc (input_location,
588 expr, BINFO_OFFSET (base));
589 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr);
590 expr = build_fold_indirect_ref_loc (input_location, expr);
591 }
592
593 return expr;
594 }
595
596
597 tree
build_vfield_ref(tree datum,tree type)598 build_vfield_ref (tree datum, tree type)
599 {
600 tree vfield, vcontext;
601
602 if (datum == error_mark_node)
603 return error_mark_node;
604
605 /* First, convert to the requested type. */
606 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
607 datum = convert_to_base (datum, type, /*check_access=*/false,
608 /*nonnull=*/true, tf_warning_or_error);
609
610 /* Second, the requested type may not be the owner of its own vptr.
611 If not, convert to the base class that owns it. We cannot use
612 convert_to_base here, because VCONTEXT may appear more than once
613 in the inheritance hierarchy of TYPE, and thus direct conversion
614 between the types may be ambiguous. Following the path back up
615 one step at a time via primary bases avoids the problem. */
616 vfield = TYPE_VFIELD (type);
617 vcontext = DECL_CONTEXT (vfield);
618 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
619 {
620 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
621 type = TREE_TYPE (datum);
622 }
623
624 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
625 }
626
627 /* Given an object INSTANCE, return an expression which yields the
628 vtable element corresponding to INDEX. There are many special
629 cases for INSTANCE which we take care of here, mainly to avoid
630 creating extra tree nodes when we don't have to. */
631
632 static tree
build_vtbl_ref_1(tree instance,tree idx)633 build_vtbl_ref_1 (tree instance, tree idx)
634 {
635 tree aref;
636 tree vtbl = NULL_TREE;
637
638 /* Try to figure out what a reference refers to, and
639 access its virtual function table directly. */
640
641 int cdtorp = 0;
642 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
643
644 tree basetype = non_reference (TREE_TYPE (instance));
645
646 if (fixed_type && !cdtorp)
647 {
648 tree binfo = lookup_base (fixed_type, basetype,
649 ba_unique, NULL, tf_none);
650 if (binfo && binfo != error_mark_node)
651 vtbl = unshare_expr (BINFO_VTABLE (binfo));
652 }
653
654 if (!vtbl)
655 vtbl = build_vfield_ref (instance, basetype);
656
657 aref = build_array_ref (input_location, vtbl, idx);
658 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
659
660 return aref;
661 }
662
663 tree
build_vtbl_ref(tree instance,tree idx)664 build_vtbl_ref (tree instance, tree idx)
665 {
666 tree aref = build_vtbl_ref_1 (instance, idx);
667
668 return aref;
669 }
670
671 /* Given a stable object pointer INSTANCE_PTR, return an expression which
672 yields a function pointer corresponding to vtable element INDEX. */
673
674 tree
build_vfn_ref(tree instance_ptr,tree idx)675 build_vfn_ref (tree instance_ptr, tree idx)
676 {
677 tree aref;
678
679 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, RO_NULL,
680 tf_warning_or_error),
681 idx);
682
683 /* When using function descriptors, the address of the
684 vtable entry is treated as a function pointer. */
685 if (TARGET_VTABLE_USES_DESCRIPTORS)
686 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
687 cp_build_addr_expr (aref, tf_warning_or_error));
688
689 /* Remember this as a method reference, for later devirtualization. */
690 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
691
692 return aref;
693 }
694
695 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
696 for the given TYPE. */
697
698 static tree
get_vtable_name(tree type)699 get_vtable_name (tree type)
700 {
701 return mangle_vtbl_for_type (type);
702 }
703
704 /* DECL is an entity associated with TYPE, like a virtual table or an
705 implicitly generated constructor. Determine whether or not DECL
706 should have external or internal linkage at the object file
707 level. This routine does not deal with COMDAT linkage and other
708 similar complexities; it simply sets TREE_PUBLIC if it possible for
709 entities in other translation units to contain copies of DECL, in
710 the abstract. */
711
712 void
set_linkage_according_to_type(tree,tree decl)713 set_linkage_according_to_type (tree /*type*/, tree decl)
714 {
715 TREE_PUBLIC (decl) = 1;
716 determine_visibility (decl);
717 }
718
719 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
720 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
721 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
722
723 static tree
build_vtable(tree class_type,tree name,tree vtable_type)724 build_vtable (tree class_type, tree name, tree vtable_type)
725 {
726 tree decl;
727
728 decl = build_lang_decl (VAR_DECL, name, vtable_type);
729 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
730 now to avoid confusion in mangle_decl. */
731 SET_DECL_ASSEMBLER_NAME (decl, name);
732 DECL_CONTEXT (decl) = class_type;
733 DECL_ARTIFICIAL (decl) = 1;
734 TREE_STATIC (decl) = 1;
735 TREE_READONLY (decl) = 1;
736 DECL_VIRTUAL_P (decl) = 1;
737 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
738 DECL_VTABLE_OR_VTT_P (decl) = 1;
739 /* At one time the vtable info was grabbed 2 words at a time. This
740 fails on sparc unless you have 8-byte alignment. (tiemann) */
741 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
742 DECL_ALIGN (decl));
743 set_linkage_according_to_type (class_type, decl);
744 /* The vtable has not been defined -- yet. */
745 DECL_EXTERNAL (decl) = 1;
746 DECL_NOT_REALLY_EXTERN (decl) = 1;
747
748 /* Mark the VAR_DECL node representing the vtable itself as a
749 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
750 is rather important that such things be ignored because any
751 effort to actually generate DWARF for them will run into
752 trouble when/if we encounter code like:
753
754 #pragma interface
755 struct S { virtual void member (); };
756
757 because the artificial declaration of the vtable itself (as
758 manufactured by the g++ front end) will say that the vtable is
759 a static member of `S' but only *after* the debug output for
760 the definition of `S' has already been output. This causes
761 grief because the DWARF entry for the definition of the vtable
762 will try to refer back to an earlier *declaration* of the
763 vtable as a static member of `S' and there won't be one. We
764 might be able to arrange to have the "vtable static member"
765 attached to the member list for `S' before the debug info for
766 `S' get written (which would solve the problem) but that would
767 require more intrusive changes to the g++ front end. */
768 DECL_IGNORED_P (decl) = 1;
769
770 return decl;
771 }
772
773 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
774 or even complete. If this does not exist, create it. If COMPLETE is
775 nonzero, then complete the definition of it -- that will render it
776 impossible to actually build the vtable, but is useful to get at those
777 which are known to exist in the runtime. */
778
779 tree
get_vtable_decl(tree type,int complete)780 get_vtable_decl (tree type, int complete)
781 {
782 tree decl;
783
784 if (CLASSTYPE_VTABLES (type))
785 return CLASSTYPE_VTABLES (type);
786
787 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
788 CLASSTYPE_VTABLES (type) = decl;
789
790 if (complete)
791 {
792 DECL_EXTERNAL (decl) = 1;
793 cp_finish_decl (decl, NULL_TREE, false, NULL_TREE, 0);
794 }
795
796 return decl;
797 }
798
799 /* Build the primary virtual function table for TYPE. If BINFO is
800 non-NULL, build the vtable starting with the initial approximation
801 that it is the same as the one which is the head of the association
802 list. Returns a nonzero value if a new vtable is actually
803 created. */
804
805 static int
build_primary_vtable(tree binfo,tree type)806 build_primary_vtable (tree binfo, tree type)
807 {
808 tree decl;
809 tree virtuals;
810
811 decl = get_vtable_decl (type, /*complete=*/0);
812
813 if (binfo)
814 {
815 if (BINFO_NEW_VTABLE_MARKED (binfo))
816 /* We have already created a vtable for this base, so there's
817 no need to do it again. */
818 return 0;
819
820 virtuals = copy_list (BINFO_VIRTUALS (binfo));
821 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
822 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
823 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
824 }
825 else
826 {
827 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
828 virtuals = NULL_TREE;
829 }
830
831 if (GATHER_STATISTICS)
832 {
833 n_vtables += 1;
834 n_vtable_elems += list_length (virtuals);
835 }
836
837 /* Initialize the association list for this type, based
838 on our first approximation. */
839 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
840 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
841 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
842 return 1;
843 }
844
845 /* Give BINFO a new virtual function table which is initialized
846 with a skeleton-copy of its original initialization. The only
847 entry that changes is the `delta' entry, so we can really
848 share a lot of structure.
849
850 FOR_TYPE is the most derived type which caused this table to
851 be needed.
852
853 Returns nonzero if we haven't met BINFO before.
854
855 The order in which vtables are built (by calling this function) for
856 an object must remain the same, otherwise a binary incompatibility
857 can result. */
858
859 static int
build_secondary_vtable(tree binfo)860 build_secondary_vtable (tree binfo)
861 {
862 if (BINFO_NEW_VTABLE_MARKED (binfo))
863 /* We already created a vtable for this base. There's no need to
864 do it again. */
865 return 0;
866
867 /* Remember that we've created a vtable for this BINFO, so that we
868 don't try to do so again. */
869 SET_BINFO_NEW_VTABLE_MARKED (binfo);
870
871 /* Make fresh virtual list, so we can smash it later. */
872 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
873
874 /* Secondary vtables are laid out as part of the same structure as
875 the primary vtable. */
876 BINFO_VTABLE (binfo) = NULL_TREE;
877 return 1;
878 }
879
880 /* Create a new vtable for BINFO which is the hierarchy dominated by
881 T. Return nonzero if we actually created a new vtable. */
882
883 static int
make_new_vtable(tree t,tree binfo)884 make_new_vtable (tree t, tree binfo)
885 {
886 if (binfo == TYPE_BINFO (t))
887 /* In this case, it is *type*'s vtable we are modifying. We start
888 with the approximation that its vtable is that of the
889 immediate base class. */
890 return build_primary_vtable (binfo, t);
891 else
892 /* This is our very own copy of `basetype' to play with. Later,
893 we will fill in all the virtual functions that override the
894 virtual functions in these base classes which are not defined
895 by the current type. */
896 return build_secondary_vtable (binfo);
897 }
898
899 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
900 (which is in the hierarchy dominated by T) list FNDECL as its
901 BV_FN. DELTA is the required constant adjustment from the `this'
902 pointer where the vtable entry appears to the `this' required when
903 the function is actually called. */
904
905 static void
modify_vtable_entry(tree t,tree binfo,tree fndecl,tree delta,tree * virtuals)906 modify_vtable_entry (tree t,
907 tree binfo,
908 tree fndecl,
909 tree delta,
910 tree *virtuals)
911 {
912 tree v;
913
914 v = *virtuals;
915
916 if (fndecl != BV_FN (v)
917 || !tree_int_cst_equal (delta, BV_DELTA (v)))
918 {
919 /* We need a new vtable for BINFO. */
920 if (make_new_vtable (t, binfo))
921 {
922 /* If we really did make a new vtable, we also made a copy
923 of the BINFO_VIRTUALS list. Now, we have to find the
924 corresponding entry in that list. */
925 *virtuals = BINFO_VIRTUALS (binfo);
926 while (BV_FN (*virtuals) != BV_FN (v))
927 *virtuals = TREE_CHAIN (*virtuals);
928 v = *virtuals;
929 }
930
931 BV_DELTA (v) = delta;
932 BV_VCALL_INDEX (v) = NULL_TREE;
933 BV_FN (v) = fndecl;
934 }
935 }
936
937
938 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
939 the USING_DECL naming METHOD. Returns true if the method could be
940 added to the method vec. */
941
942 bool
add_method(tree type,tree method,tree using_decl)943 add_method (tree type, tree method, tree using_decl)
944 {
945 unsigned slot;
946 tree overload;
947 bool template_conv_p = false;
948 bool conv_p;
949 vec<tree, va_gc> *method_vec;
950 bool complete_p;
951 bool insert_p = false;
952 tree current_fns;
953 tree fns;
954
955 if (method == error_mark_node)
956 return false;
957
958 complete_p = COMPLETE_TYPE_P (type);
959 conv_p = DECL_CONV_FN_P (method);
960 if (conv_p)
961 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
962 && DECL_TEMPLATE_CONV_FN_P (method));
963
964 method_vec = CLASSTYPE_METHOD_VEC (type);
965 if (!method_vec)
966 {
967 /* Make a new method vector. We start with 8 entries. We must
968 allocate at least two (for constructors and destructors), and
969 we're going to end up with an assignment operator at some
970 point as well. */
971 vec_alloc (method_vec, 8);
972 /* Create slots for constructors and destructors. */
973 method_vec->quick_push (NULL_TREE);
974 method_vec->quick_push (NULL_TREE);
975 CLASSTYPE_METHOD_VEC (type) = method_vec;
976 }
977
978 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
979 grok_special_member_properties (method);
980
981 /* Constructors and destructors go in special slots. */
982 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
983 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
984 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
985 {
986 slot = CLASSTYPE_DESTRUCTOR_SLOT;
987
988 if (TYPE_FOR_JAVA (type))
989 {
990 if (!DECL_ARTIFICIAL (method))
991 error ("Java class %qT cannot have a destructor", type);
992 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
993 error ("Java class %qT cannot have an implicit non-trivial "
994 "destructor",
995 type);
996 }
997 }
998 else
999 {
1000 tree m;
1001
1002 insert_p = true;
1003 /* See if we already have an entry with this name. */
1004 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1005 vec_safe_iterate (method_vec, slot, &m);
1006 ++slot)
1007 {
1008 m = OVL_CURRENT (m);
1009 if (template_conv_p)
1010 {
1011 if (TREE_CODE (m) == TEMPLATE_DECL
1012 && DECL_TEMPLATE_CONV_FN_P (m))
1013 insert_p = false;
1014 break;
1015 }
1016 if (conv_p && !DECL_CONV_FN_P (m))
1017 break;
1018 if (DECL_NAME (m) == DECL_NAME (method))
1019 {
1020 insert_p = false;
1021 break;
1022 }
1023 if (complete_p
1024 && !DECL_CONV_FN_P (m)
1025 && DECL_NAME (m) > DECL_NAME (method))
1026 break;
1027 }
1028 }
1029 current_fns = insert_p ? NULL_TREE : (*method_vec)[slot];
1030
1031 /* Check to see if we've already got this method. */
1032 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
1033 {
1034 tree fn = OVL_CURRENT (fns);
1035 tree fn_type;
1036 tree method_type;
1037 tree parms1;
1038 tree parms2;
1039
1040 if (TREE_CODE (fn) != TREE_CODE (method))
1041 continue;
1042
1043 /* [over.load] Member function declarations with the
1044 same name and the same parameter types cannot be
1045 overloaded if any of them is a static member
1046 function declaration.
1047
1048 [over.load] Member function declarations with the same name and
1049 the same parameter-type-list as well as member function template
1050 declarations with the same name, the same parameter-type-list, and
1051 the same template parameter lists cannot be overloaded if any of
1052 them, but not all, have a ref-qualifier.
1053
1054 [namespace.udecl] When a using-declaration brings names
1055 from a base class into a derived class scope, member
1056 functions in the derived class override and/or hide member
1057 functions with the same name and parameter types in a base
1058 class (rather than conflicting). */
1059 fn_type = TREE_TYPE (fn);
1060 method_type = TREE_TYPE (method);
1061 parms1 = TYPE_ARG_TYPES (fn_type);
1062 parms2 = TYPE_ARG_TYPES (method_type);
1063
1064 /* Compare the quals on the 'this' parm. Don't compare
1065 the whole types, as used functions are treated as
1066 coming from the using class in overload resolution. */
1067 if (! DECL_STATIC_FUNCTION_P (fn)
1068 && ! DECL_STATIC_FUNCTION_P (method)
1069 /* Either both or neither need to be ref-qualified for
1070 differing quals to allow overloading. */
1071 && (FUNCTION_REF_QUALIFIED (fn_type)
1072 == FUNCTION_REF_QUALIFIED (method_type))
1073 && (type_memfn_quals (fn_type) != type_memfn_quals (method_type)
1074 || type_memfn_rqual (fn_type) != type_memfn_rqual (method_type)))
1075 continue;
1076
1077 /* For templates, the return type and template parameters
1078 must be identical. */
1079 if (TREE_CODE (fn) == TEMPLATE_DECL
1080 && (!same_type_p (TREE_TYPE (fn_type),
1081 TREE_TYPE (method_type))
1082 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1083 DECL_TEMPLATE_PARMS (method))))
1084 continue;
1085
1086 if (! DECL_STATIC_FUNCTION_P (fn))
1087 parms1 = TREE_CHAIN (parms1);
1088 if (! DECL_STATIC_FUNCTION_P (method))
1089 parms2 = TREE_CHAIN (parms2);
1090
1091 if (compparms (parms1, parms2)
1092 && (!DECL_CONV_FN_P (fn)
1093 || same_type_p (TREE_TYPE (fn_type),
1094 TREE_TYPE (method_type))))
1095 {
1096 /* For function versions, their parms and types match
1097 but they are not duplicates. Record function versions
1098 as and when they are found. extern "C" functions are
1099 not treated as versions. */
1100 if (TREE_CODE (fn) == FUNCTION_DECL
1101 && TREE_CODE (method) == FUNCTION_DECL
1102 && !DECL_EXTERN_C_P (fn)
1103 && !DECL_EXTERN_C_P (method)
1104 && targetm.target_option.function_versions (fn, method))
1105 {
1106 /* Mark functions as versions if necessary. Modify the mangled
1107 decl name if necessary. */
1108 if (!DECL_FUNCTION_VERSIONED (fn))
1109 {
1110 DECL_FUNCTION_VERSIONED (fn) = 1;
1111 if (DECL_ASSEMBLER_NAME_SET_P (fn))
1112 mangle_decl (fn);
1113 }
1114 if (!DECL_FUNCTION_VERSIONED (method))
1115 {
1116 DECL_FUNCTION_VERSIONED (method) = 1;
1117 if (DECL_ASSEMBLER_NAME_SET_P (method))
1118 mangle_decl (method);
1119 }
1120 record_function_versions (fn, method);
1121 continue;
1122 }
1123 if (DECL_INHERITED_CTOR_BASE (method))
1124 {
1125 if (DECL_INHERITED_CTOR_BASE (fn))
1126 {
1127 error_at (DECL_SOURCE_LOCATION (method),
1128 "%q#D inherited from %qT", method,
1129 DECL_INHERITED_CTOR_BASE (method));
1130 error_at (DECL_SOURCE_LOCATION (fn),
1131 "conflicts with version inherited from %qT",
1132 DECL_INHERITED_CTOR_BASE (fn));
1133 }
1134 /* Otherwise defer to the other function. */
1135 return false;
1136 }
1137 if (using_decl)
1138 {
1139 if (DECL_CONTEXT (fn) == type)
1140 /* Defer to the local function. */
1141 return false;
1142 }
1143 else
1144 {
1145 error ("%q+#D cannot be overloaded", method);
1146 error ("with %q+#D", fn);
1147 }
1148
1149 /* We don't call duplicate_decls here to merge the
1150 declarations because that will confuse things if the
1151 methods have inline definitions. In particular, we
1152 will crash while processing the definitions. */
1153 return false;
1154 }
1155 }
1156
1157 /* A class should never have more than one destructor. */
1158 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1159 return false;
1160
1161 /* Add the new binding. */
1162 if (using_decl)
1163 {
1164 overload = ovl_cons (method, current_fns);
1165 OVL_USED (overload) = true;
1166 }
1167 else
1168 overload = build_overload (method, current_fns);
1169
1170 if (conv_p)
1171 TYPE_HAS_CONVERSION (type) = 1;
1172 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1173 push_class_level_binding (DECL_NAME (method), overload);
1174
1175 if (insert_p)
1176 {
1177 bool reallocated;
1178
1179 /* We only expect to add few methods in the COMPLETE_P case, so
1180 just make room for one more method in that case. */
1181 if (complete_p)
1182 reallocated = vec_safe_reserve_exact (method_vec, 1);
1183 else
1184 reallocated = vec_safe_reserve (method_vec, 1);
1185 if (reallocated)
1186 CLASSTYPE_METHOD_VEC (type) = method_vec;
1187 if (slot == method_vec->length ())
1188 method_vec->quick_push (overload);
1189 else
1190 method_vec->quick_insert (slot, overload);
1191 }
1192 else
1193 /* Replace the current slot. */
1194 (*method_vec)[slot] = overload;
1195 return true;
1196 }
1197
1198 /* Subroutines of finish_struct. */
1199
1200 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1201 legit, otherwise return 0. */
1202
1203 static int
alter_access(tree t,tree fdecl,tree access)1204 alter_access (tree t, tree fdecl, tree access)
1205 {
1206 tree elem;
1207
1208 if (!DECL_LANG_SPECIFIC (fdecl))
1209 retrofit_lang_decl (fdecl);
1210
1211 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1212
1213 elem = purpose_member (t, DECL_ACCESS (fdecl));
1214 if (elem)
1215 {
1216 if (TREE_VALUE (elem) != access)
1217 {
1218 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1219 error ("conflicting access specifications for method"
1220 " %q+D, ignored", TREE_TYPE (fdecl));
1221 else
1222 error ("conflicting access specifications for field %qE, ignored",
1223 DECL_NAME (fdecl));
1224 }
1225 else
1226 {
1227 /* They're changing the access to the same thing they changed
1228 it to before. That's OK. */
1229 ;
1230 }
1231 }
1232 else
1233 {
1234 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl,
1235 tf_warning_or_error);
1236 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1237 return 1;
1238 }
1239 return 0;
1240 }
1241
1242 /* Process the USING_DECL, which is a member of T. */
1243
1244 static void
handle_using_decl(tree using_decl,tree t)1245 handle_using_decl (tree using_decl, tree t)
1246 {
1247 tree decl = USING_DECL_DECLS (using_decl);
1248 tree name = DECL_NAME (using_decl);
1249 tree access
1250 = TREE_PRIVATE (using_decl) ? access_private_node
1251 : TREE_PROTECTED (using_decl) ? access_protected_node
1252 : access_public_node;
1253 tree flist = NULL_TREE;
1254 tree old_value;
1255
1256 gcc_assert (!processing_template_decl && decl);
1257
1258 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false,
1259 tf_warning_or_error);
1260 if (old_value)
1261 {
1262 if (is_overloaded_fn (old_value))
1263 old_value = OVL_CURRENT (old_value);
1264
1265 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1266 /* OK */;
1267 else
1268 old_value = NULL_TREE;
1269 }
1270
1271 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1272
1273 if (is_overloaded_fn (decl))
1274 flist = decl;
1275
1276 if (! old_value)
1277 ;
1278 else if (is_overloaded_fn (old_value))
1279 {
1280 if (flist)
1281 /* It's OK to use functions from a base when there are functions with
1282 the same name already present in the current class. */;
1283 else
1284 {
1285 error ("%q+D invalid in %q#T", using_decl, t);
1286 error (" because of local method %q+#D with same name",
1287 OVL_CURRENT (old_value));
1288 return;
1289 }
1290 }
1291 else if (!DECL_ARTIFICIAL (old_value))
1292 {
1293 error ("%q+D invalid in %q#T", using_decl, t);
1294 error (" because of local member %q+#D with same name", old_value);
1295 return;
1296 }
1297
1298 /* Make type T see field decl FDECL with access ACCESS. */
1299 if (flist)
1300 for (; flist; flist = OVL_NEXT (flist))
1301 {
1302 add_method (t, OVL_CURRENT (flist), using_decl);
1303 alter_access (t, OVL_CURRENT (flist), access);
1304 }
1305 else
1306 alter_access (t, decl, access);
1307 }
1308
1309 /* walk_tree callback for check_abi_tags: if the type at *TP involves any
1310 types with abi tags, add the corresponding identifiers to the VEC in
1311 *DATA and set IDENTIFIER_MARKED. */
1312
1313 struct abi_tag_data
1314 {
1315 tree t;
1316 tree subob;
1317 };
1318
1319 static tree
find_abi_tags_r(tree * tp,int *,void * data)1320 find_abi_tags_r (tree *tp, int */*walk_subtrees*/, void *data)
1321 {
1322 if (!TAGGED_TYPE_P (*tp))
1323 return NULL_TREE;
1324
1325 if (tree attributes = lookup_attribute ("abi_tag", TYPE_ATTRIBUTES (*tp)))
1326 {
1327 struct abi_tag_data *p = static_cast<struct abi_tag_data*>(data);
1328 for (tree list = TREE_VALUE (attributes); list;
1329 list = TREE_CHAIN (list))
1330 {
1331 tree tag = TREE_VALUE (list);
1332 tree id = get_identifier (TREE_STRING_POINTER (tag));
1333 if (!IDENTIFIER_MARKED (id))
1334 {
1335 if (TYPE_P (p->subob))
1336 {
1337 warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
1338 "that base %qT has", p->t, tag, p->subob);
1339 inform (location_of (p->subob), "%qT declared here",
1340 p->subob);
1341 }
1342 else
1343 {
1344 warning (OPT_Wabi_tag, "%qT does not have the %E abi tag "
1345 "that %qT (used in the type of %qD) has",
1346 p->t, tag, *tp, p->subob);
1347 inform (location_of (p->subob), "%qD declared here",
1348 p->subob);
1349 inform (location_of (*tp), "%qT declared here", *tp);
1350 }
1351 }
1352 }
1353 }
1354 return NULL_TREE;
1355 }
1356
1357 /* Check that class T has all the abi tags that subobject SUBOB has, or
1358 warn if not. */
1359
1360 static void
check_abi_tags(tree t,tree subob)1361 check_abi_tags (tree t, tree subob)
1362 {
1363 tree attributes = lookup_attribute ("abi_tag", TYPE_ATTRIBUTES (t));
1364 if (attributes)
1365 {
1366 for (tree list = TREE_VALUE (attributes); list;
1367 list = TREE_CHAIN (list))
1368 {
1369 tree tag = TREE_VALUE (list);
1370 tree id = get_identifier (TREE_STRING_POINTER (tag));
1371 IDENTIFIER_MARKED (id) = true;
1372 }
1373 }
1374
1375 tree subtype = TYPE_P (subob) ? subob : TREE_TYPE (subob);
1376 struct abi_tag_data data = { t, subob };
1377
1378 cp_walk_tree_without_duplicates (&subtype, find_abi_tags_r, &data);
1379
1380 if (attributes)
1381 {
1382 for (tree list = TREE_VALUE (attributes); list;
1383 list = TREE_CHAIN (list))
1384 {
1385 tree tag = TREE_VALUE (list);
1386 tree id = get_identifier (TREE_STRING_POINTER (tag));
1387 IDENTIFIER_MARKED (id) = false;
1388 }
1389 }
1390 }
1391
1392 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1393 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1394 properties of the bases. */
1395
1396 static void
check_bases(tree t,int * cant_have_const_ctor_p,int * no_const_asn_ref_p)1397 check_bases (tree t,
1398 int* cant_have_const_ctor_p,
1399 int* no_const_asn_ref_p)
1400 {
1401 int i;
1402 bool seen_non_virtual_nearly_empty_base_p = 0;
1403 int seen_tm_mask = 0;
1404 tree base_binfo;
1405 tree binfo;
1406 tree field = NULL_TREE;
1407
1408 if (!CLASSTYPE_NON_STD_LAYOUT (t))
1409 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
1410 if (TREE_CODE (field) == FIELD_DECL)
1411 break;
1412
1413 for (binfo = TYPE_BINFO (t), i = 0;
1414 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1415 {
1416 tree basetype = TREE_TYPE (base_binfo);
1417
1418 gcc_assert (COMPLETE_TYPE_P (basetype));
1419
1420 if (CLASSTYPE_FINAL (basetype))
1421 error ("cannot derive from %<final%> base %qT in derived type %qT",
1422 basetype, t);
1423
1424 /* If any base class is non-literal, so is the derived class. */
1425 if (!CLASSTYPE_LITERAL_P (basetype))
1426 CLASSTYPE_LITERAL_P (t) = false;
1427
1428 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1429 here because the case of virtual functions but non-virtual
1430 dtor is handled in finish_struct_1. */
1431 if (!TYPE_POLYMORPHIC_P (basetype))
1432 warning (OPT_Weffc__,
1433 "base class %q#T has a non-virtual destructor", basetype);
1434
1435 /* If the base class doesn't have copy constructors or
1436 assignment operators that take const references, then the
1437 derived class cannot have such a member automatically
1438 generated. */
1439 if (TYPE_HAS_COPY_CTOR (basetype)
1440 && ! TYPE_HAS_CONST_COPY_CTOR (basetype))
1441 *cant_have_const_ctor_p = 1;
1442 if (TYPE_HAS_COPY_ASSIGN (basetype)
1443 && !TYPE_HAS_CONST_COPY_ASSIGN (basetype))
1444 *no_const_asn_ref_p = 1;
1445
1446 if (BINFO_VIRTUAL_P (base_binfo))
1447 /* A virtual base does not effect nearly emptiness. */
1448 ;
1449 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1450 {
1451 if (seen_non_virtual_nearly_empty_base_p)
1452 /* And if there is more than one nearly empty base, then the
1453 derived class is not nearly empty either. */
1454 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1455 else
1456 /* Remember we've seen one. */
1457 seen_non_virtual_nearly_empty_base_p = 1;
1458 }
1459 else if (!is_empty_class (basetype))
1460 /* If the base class is not empty or nearly empty, then this
1461 class cannot be nearly empty. */
1462 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1463
1464 /* A lot of properties from the bases also apply to the derived
1465 class. */
1466 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1467 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1468 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1469 TYPE_HAS_COMPLEX_COPY_ASSIGN (t)
1470 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (basetype)
1471 || !TYPE_HAS_COPY_ASSIGN (basetype));
1472 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (basetype)
1473 || !TYPE_HAS_COPY_CTOR (basetype));
1474 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t)
1475 |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (basetype);
1476 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (basetype);
1477 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1478 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1479 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1480 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
1481 || TYPE_HAS_COMPLEX_DFLT (basetype));
1482
1483 /* A standard-layout class is a class that:
1484 ...
1485 * has no non-standard-layout base classes, */
1486 CLASSTYPE_NON_STD_LAYOUT (t) |= CLASSTYPE_NON_STD_LAYOUT (basetype);
1487 if (!CLASSTYPE_NON_STD_LAYOUT (t))
1488 {
1489 tree basefield;
1490 /* ...has no base classes of the same type as the first non-static
1491 data member... */
1492 if (field && DECL_CONTEXT (field) == t
1493 && (same_type_ignoring_top_level_qualifiers_p
1494 (TREE_TYPE (field), basetype)))
1495 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
1496 else
1497 /* ...either has no non-static data members in the most-derived
1498 class and at most one base class with non-static data
1499 members, or has no base classes with non-static data
1500 members */
1501 for (basefield = TYPE_FIELDS (basetype); basefield;
1502 basefield = DECL_CHAIN (basefield))
1503 if (TREE_CODE (basefield) == FIELD_DECL)
1504 {
1505 if (field)
1506 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
1507 else
1508 field = basefield;
1509 break;
1510 }
1511 }
1512
1513 /* Don't bother collecting tm attributes if transactional memory
1514 support is not enabled. */
1515 if (flag_tm)
1516 {
1517 tree tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (basetype));
1518 if (tm_attr)
1519 seen_tm_mask |= tm_attr_to_mask (tm_attr);
1520 }
1521
1522 check_abi_tags (t, basetype);
1523 }
1524
1525 /* If one of the base classes had TM attributes, and the current class
1526 doesn't define its own, then the current class inherits one. */
1527 if (seen_tm_mask && !find_tm_attribute (TYPE_ATTRIBUTES (t)))
1528 {
1529 tree tm_attr = tm_mask_to_attr (seen_tm_mask & -seen_tm_mask);
1530 TYPE_ATTRIBUTES (t) = tree_cons (tm_attr, NULL, TYPE_ATTRIBUTES (t));
1531 }
1532 }
1533
1534 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1535 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1536 that have had a nearly-empty virtual primary base stolen by some
1537 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1538 T. */
1539
1540 static void
determine_primary_bases(tree t)1541 determine_primary_bases (tree t)
1542 {
1543 unsigned i;
1544 tree primary = NULL_TREE;
1545 tree type_binfo = TYPE_BINFO (t);
1546 tree base_binfo;
1547
1548 /* Determine the primary bases of our bases. */
1549 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1550 base_binfo = TREE_CHAIN (base_binfo))
1551 {
1552 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1553
1554 /* See if we're the non-virtual primary of our inheritance
1555 chain. */
1556 if (!BINFO_VIRTUAL_P (base_binfo))
1557 {
1558 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1559 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1560
1561 if (parent_primary
1562 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1563 BINFO_TYPE (parent_primary)))
1564 /* We are the primary binfo. */
1565 BINFO_PRIMARY_P (base_binfo) = 1;
1566 }
1567 /* Determine if we have a virtual primary base, and mark it so.
1568 */
1569 if (primary && BINFO_VIRTUAL_P (primary))
1570 {
1571 tree this_primary = copied_binfo (primary, base_binfo);
1572
1573 if (BINFO_PRIMARY_P (this_primary))
1574 /* Someone already claimed this base. */
1575 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1576 else
1577 {
1578 tree delta;
1579
1580 BINFO_PRIMARY_P (this_primary) = 1;
1581 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1582
1583 /* A virtual binfo might have been copied from within
1584 another hierarchy. As we're about to use it as a
1585 primary base, make sure the offsets match. */
1586 delta = size_diffop_loc (input_location,
1587 convert (ssizetype,
1588 BINFO_OFFSET (base_binfo)),
1589 convert (ssizetype,
1590 BINFO_OFFSET (this_primary)));
1591
1592 propagate_binfo_offsets (this_primary, delta);
1593 }
1594 }
1595 }
1596
1597 /* First look for a dynamic direct non-virtual base. */
1598 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1599 {
1600 tree basetype = BINFO_TYPE (base_binfo);
1601
1602 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1603 {
1604 primary = base_binfo;
1605 goto found;
1606 }
1607 }
1608
1609 /* A "nearly-empty" virtual base class can be the primary base
1610 class, if no non-virtual polymorphic base can be found. Look for
1611 a nearly-empty virtual dynamic base that is not already a primary
1612 base of something in the hierarchy. If there is no such base,
1613 just pick the first nearly-empty virtual base. */
1614
1615 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1616 base_binfo = TREE_CHAIN (base_binfo))
1617 if (BINFO_VIRTUAL_P (base_binfo)
1618 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1619 {
1620 if (!BINFO_PRIMARY_P (base_binfo))
1621 {
1622 /* Found one that is not primary. */
1623 primary = base_binfo;
1624 goto found;
1625 }
1626 else if (!primary)
1627 /* Remember the first candidate. */
1628 primary = base_binfo;
1629 }
1630
1631 found:
1632 /* If we've got a primary base, use it. */
1633 if (primary)
1634 {
1635 tree basetype = BINFO_TYPE (primary);
1636
1637 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1638 if (BINFO_PRIMARY_P (primary))
1639 /* We are stealing a primary base. */
1640 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1641 BINFO_PRIMARY_P (primary) = 1;
1642 if (BINFO_VIRTUAL_P (primary))
1643 {
1644 tree delta;
1645
1646 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1647 /* A virtual binfo might have been copied from within
1648 another hierarchy. As we're about to use it as a primary
1649 base, make sure the offsets match. */
1650 delta = size_diffop_loc (input_location, ssize_int (0),
1651 convert (ssizetype, BINFO_OFFSET (primary)));
1652
1653 propagate_binfo_offsets (primary, delta);
1654 }
1655
1656 primary = TYPE_BINFO (basetype);
1657
1658 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1659 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1660 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1661 }
1662 }
1663
1664 /* Update the variant types of T. */
1665
1666 void
fixup_type_variants(tree t)1667 fixup_type_variants (tree t)
1668 {
1669 tree variants;
1670
1671 if (!t)
1672 return;
1673
1674 for (variants = TYPE_NEXT_VARIANT (t);
1675 variants;
1676 variants = TYPE_NEXT_VARIANT (variants))
1677 {
1678 /* These fields are in the _TYPE part of the node, not in
1679 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1680 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
1681 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1682 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1683 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1684
1685 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1686
1687 TYPE_BINFO (variants) = TYPE_BINFO (t);
1688
1689 /* Copy whatever these are holding today. */
1690 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1691 TYPE_METHODS (variants) = TYPE_METHODS (t);
1692 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1693 }
1694 }
1695
1696 /* Early variant fixups: we apply attributes at the beginning of the class
1697 definition, and we need to fix up any variants that have already been
1698 made via elaborated-type-specifier so that check_qualified_type works. */
1699
1700 void
fixup_attribute_variants(tree t)1701 fixup_attribute_variants (tree t)
1702 {
1703 tree variants;
1704
1705 if (!t)
1706 return;
1707
1708 for (variants = TYPE_NEXT_VARIANT (t);
1709 variants;
1710 variants = TYPE_NEXT_VARIANT (variants))
1711 {
1712 /* These are the two fields that check_qualified_type looks at and
1713 are affected by attributes. */
1714 TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t);
1715 TYPE_ALIGN (variants) = TYPE_ALIGN (t);
1716 }
1717 }
1718
1719 /* Set memoizing fields and bits of T (and its variants) for later
1720 use. */
1721
1722 static void
finish_struct_bits(tree t)1723 finish_struct_bits (tree t)
1724 {
1725 /* Fix up variants (if any). */
1726 fixup_type_variants (t);
1727
1728 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1729 /* For a class w/o baseclasses, 'finish_struct' has set
1730 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1731 Similarly for a class whose base classes do not have vtables.
1732 When neither of these is true, we might have removed abstract
1733 virtuals (by providing a definition), added some (by declaring
1734 new ones), or redeclared ones from a base class. We need to
1735 recalculate what's really an abstract virtual at this point (by
1736 looking in the vtables). */
1737 get_pure_virtuals (t);
1738
1739 /* If this type has a copy constructor or a destructor, force its
1740 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1741 nonzero. This will cause it to be passed by invisible reference
1742 and prevent it from being returned in a register. */
1743 if (type_has_nontrivial_copy_init (t)
1744 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1745 {
1746 tree variants;
1747 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1748 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1749 {
1750 SET_TYPE_MODE (variants, BLKmode);
1751 TREE_ADDRESSABLE (variants) = 1;
1752 }
1753 }
1754 }
1755
1756 /* Issue warnings about T having private constructors, but no friends,
1757 and so forth.
1758
1759 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1760 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1761 non-private static member functions. */
1762
1763 static void
maybe_warn_about_overly_private_class(tree t)1764 maybe_warn_about_overly_private_class (tree t)
1765 {
1766 int has_member_fn = 0;
1767 int has_nonprivate_method = 0;
1768 tree fn;
1769
1770 if (!warn_ctor_dtor_privacy
1771 /* If the class has friends, those entities might create and
1772 access instances, so we should not warn. */
1773 || (CLASSTYPE_FRIEND_CLASSES (t)
1774 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1775 /* We will have warned when the template was declared; there's
1776 no need to warn on every instantiation. */
1777 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1778 /* There's no reason to even consider warning about this
1779 class. */
1780 return;
1781
1782 /* We only issue one warning, if more than one applies, because
1783 otherwise, on code like:
1784
1785 class A {
1786 // Oops - forgot `public:'
1787 A();
1788 A(const A&);
1789 ~A();
1790 };
1791
1792 we warn several times about essentially the same problem. */
1793
1794 /* Check to see if all (non-constructor, non-destructor) member
1795 functions are private. (Since there are no friends or
1796 non-private statics, we can't ever call any of the private member
1797 functions.) */
1798 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn))
1799 /* We're not interested in compiler-generated methods; they don't
1800 provide any way to call private members. */
1801 if (!DECL_ARTIFICIAL (fn))
1802 {
1803 if (!TREE_PRIVATE (fn))
1804 {
1805 if (DECL_STATIC_FUNCTION_P (fn))
1806 /* A non-private static member function is just like a
1807 friend; it can create and invoke private member
1808 functions, and be accessed without a class
1809 instance. */
1810 return;
1811
1812 has_nonprivate_method = 1;
1813 /* Keep searching for a static member function. */
1814 }
1815 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1816 has_member_fn = 1;
1817 }
1818
1819 if (!has_nonprivate_method && has_member_fn)
1820 {
1821 /* There are no non-private methods, and there's at least one
1822 private member function that isn't a constructor or
1823 destructor. (If all the private members are
1824 constructors/destructors we want to use the code below that
1825 issues error messages specifically referring to
1826 constructors/destructors.) */
1827 unsigned i;
1828 tree binfo = TYPE_BINFO (t);
1829
1830 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1831 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1832 {
1833 has_nonprivate_method = 1;
1834 break;
1835 }
1836 if (!has_nonprivate_method)
1837 {
1838 warning (OPT_Wctor_dtor_privacy,
1839 "all member functions in class %qT are private", t);
1840 return;
1841 }
1842 }
1843
1844 /* Even if some of the member functions are non-private, the class
1845 won't be useful for much if all the constructors or destructors
1846 are private: such an object can never be created or destroyed. */
1847 fn = CLASSTYPE_DESTRUCTORS (t);
1848 if (fn && TREE_PRIVATE (fn))
1849 {
1850 warning (OPT_Wctor_dtor_privacy,
1851 "%q#T only defines a private destructor and has no friends",
1852 t);
1853 return;
1854 }
1855
1856 /* Warn about classes that have private constructors and no friends. */
1857 if (TYPE_HAS_USER_CONSTRUCTOR (t)
1858 /* Implicitly generated constructors are always public. */
1859 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1860 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1861 {
1862 int nonprivate_ctor = 0;
1863
1864 /* If a non-template class does not define a copy
1865 constructor, one is defined for it, enabling it to avoid
1866 this warning. For a template class, this does not
1867 happen, and so we would normally get a warning on:
1868
1869 template <class T> class C { private: C(); };
1870
1871 To avoid this asymmetry, we check TYPE_HAS_COPY_CTOR. All
1872 complete non-template or fully instantiated classes have this
1873 flag set. */
1874 if (!TYPE_HAS_COPY_CTOR (t))
1875 nonprivate_ctor = 1;
1876 else
1877 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1878 {
1879 tree ctor = OVL_CURRENT (fn);
1880 /* Ideally, we wouldn't count copy constructors (or, in
1881 fact, any constructor that takes an argument of the
1882 class type as a parameter) because such things cannot
1883 be used to construct an instance of the class unless
1884 you already have one. But, for now at least, we're
1885 more generous. */
1886 if (! TREE_PRIVATE (ctor))
1887 {
1888 nonprivate_ctor = 1;
1889 break;
1890 }
1891 }
1892
1893 if (nonprivate_ctor == 0)
1894 {
1895 warning (OPT_Wctor_dtor_privacy,
1896 "%q#T only defines private constructors and has no friends",
1897 t);
1898 return;
1899 }
1900 }
1901 }
1902
1903 static struct {
1904 gt_pointer_operator new_value;
1905 void *cookie;
1906 } resort_data;
1907
1908 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1909
1910 static int
method_name_cmp(const void * m1_p,const void * m2_p)1911 method_name_cmp (const void* m1_p, const void* m2_p)
1912 {
1913 const tree *const m1 = (const tree *) m1_p;
1914 const tree *const m2 = (const tree *) m2_p;
1915
1916 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1917 return 0;
1918 if (*m1 == NULL_TREE)
1919 return -1;
1920 if (*m2 == NULL_TREE)
1921 return 1;
1922 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1923 return -1;
1924 return 1;
1925 }
1926
1927 /* This routine compares two fields like method_name_cmp but using the
1928 pointer operator in resort_field_decl_data. */
1929
1930 static int
resort_method_name_cmp(const void * m1_p,const void * m2_p)1931 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1932 {
1933 const tree *const m1 = (const tree *) m1_p;
1934 const tree *const m2 = (const tree *) m2_p;
1935 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1936 return 0;
1937 if (*m1 == NULL_TREE)
1938 return -1;
1939 if (*m2 == NULL_TREE)
1940 return 1;
1941 {
1942 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1943 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1944 resort_data.new_value (&d1, resort_data.cookie);
1945 resort_data.new_value (&d2, resort_data.cookie);
1946 if (d1 < d2)
1947 return -1;
1948 }
1949 return 1;
1950 }
1951
1952 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1953
1954 void
resort_type_method_vec(void * obj,void *,gt_pointer_operator new_value,void * cookie)1955 resort_type_method_vec (void* obj,
1956 void* /*orig_obj*/,
1957 gt_pointer_operator new_value,
1958 void* cookie)
1959 {
1960 vec<tree, va_gc> *method_vec = (vec<tree, va_gc> *) obj;
1961 int len = vec_safe_length (method_vec);
1962 size_t slot;
1963 tree fn;
1964
1965 /* The type conversion ops have to live at the front of the vec, so we
1966 can't sort them. */
1967 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1968 vec_safe_iterate (method_vec, slot, &fn);
1969 ++slot)
1970 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1971 break;
1972
1973 if (len - slot > 1)
1974 {
1975 resort_data.new_value = new_value;
1976 resort_data.cookie = cookie;
1977 qsort (method_vec->address () + slot, len - slot, sizeof (tree),
1978 resort_method_name_cmp);
1979 }
1980 }
1981
1982 /* Warn about duplicate methods in fn_fields.
1983
1984 Sort methods that are not special (i.e., constructors, destructors,
1985 and type conversion operators) so that we can find them faster in
1986 search. */
1987
1988 static void
finish_struct_methods(tree t)1989 finish_struct_methods (tree t)
1990 {
1991 tree fn_fields;
1992 vec<tree, va_gc> *method_vec;
1993 int slot, len;
1994
1995 method_vec = CLASSTYPE_METHOD_VEC (t);
1996 if (!method_vec)
1997 return;
1998
1999 len = method_vec->length ();
2000
2001 /* Clear DECL_IN_AGGR_P for all functions. */
2002 for (fn_fields = TYPE_METHODS (t); fn_fields;
2003 fn_fields = DECL_CHAIN (fn_fields))
2004 DECL_IN_AGGR_P (fn_fields) = 0;
2005
2006 /* Issue warnings about private constructors and such. If there are
2007 no methods, then some public defaults are generated. */
2008 maybe_warn_about_overly_private_class (t);
2009
2010 /* The type conversion ops have to live at the front of the vec, so we
2011 can't sort them. */
2012 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
2013 method_vec->iterate (slot, &fn_fields);
2014 ++slot)
2015 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
2016 break;
2017 if (len - slot > 1)
2018 qsort (method_vec->address () + slot,
2019 len-slot, sizeof (tree), method_name_cmp);
2020 }
2021
2022 /* Make BINFO's vtable have N entries, including RTTI entries,
2023 vbase and vcall offsets, etc. Set its type and call the back end
2024 to lay it out. */
2025
2026 static void
layout_vtable_decl(tree binfo,int n)2027 layout_vtable_decl (tree binfo, int n)
2028 {
2029 tree atype;
2030 tree vtable;
2031
2032 atype = build_array_of_n_type (vtable_entry_type, n);
2033 layout_type (atype);
2034
2035 /* We may have to grow the vtable. */
2036 vtable = get_vtbl_decl_for_binfo (binfo);
2037 if (!same_type_p (TREE_TYPE (vtable), atype))
2038 {
2039 TREE_TYPE (vtable) = atype;
2040 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
2041 layout_decl (vtable, 0);
2042 }
2043 }
2044
2045 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
2046 have the same signature. */
2047
2048 int
same_signature_p(const_tree fndecl,const_tree base_fndecl)2049 same_signature_p (const_tree fndecl, const_tree base_fndecl)
2050 {
2051 /* One destructor overrides another if they are the same kind of
2052 destructor. */
2053 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
2054 && special_function_p (base_fndecl) == special_function_p (fndecl))
2055 return 1;
2056 /* But a non-destructor never overrides a destructor, nor vice
2057 versa, nor do different kinds of destructors override
2058 one-another. For example, a complete object destructor does not
2059 override a deleting destructor. */
2060 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
2061 return 0;
2062
2063 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
2064 || (DECL_CONV_FN_P (fndecl)
2065 && DECL_CONV_FN_P (base_fndecl)
2066 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
2067 DECL_CONV_FN_TYPE (base_fndecl))))
2068 {
2069 tree types, base_types;
2070 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
2071 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
2072 if ((cp_type_quals (TREE_TYPE (TREE_VALUE (base_types)))
2073 == cp_type_quals (TREE_TYPE (TREE_VALUE (types))))
2074 && (type_memfn_rqual (TREE_TYPE (fndecl))
2075 == type_memfn_rqual (TREE_TYPE (base_fndecl)))
2076 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
2077 return 1;
2078 }
2079 return 0;
2080 }
2081
2082 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
2083 subobject. */
2084
2085 static bool
base_derived_from(tree derived,tree base)2086 base_derived_from (tree derived, tree base)
2087 {
2088 tree probe;
2089
2090 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
2091 {
2092 if (probe == derived)
2093 return true;
2094 else if (BINFO_VIRTUAL_P (probe))
2095 /* If we meet a virtual base, we can't follow the inheritance
2096 any more. See if the complete type of DERIVED contains
2097 such a virtual base. */
2098 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
2099 != NULL_TREE);
2100 }
2101 return false;
2102 }
2103
2104 typedef struct find_final_overrider_data_s {
2105 /* The function for which we are trying to find a final overrider. */
2106 tree fn;
2107 /* The base class in which the function was declared. */
2108 tree declaring_base;
2109 /* The candidate overriders. */
2110 tree candidates;
2111 /* Path to most derived. */
2112 vec<tree> path;
2113 } find_final_overrider_data;
2114
2115 /* Add the overrider along the current path to FFOD->CANDIDATES.
2116 Returns true if an overrider was found; false otherwise. */
2117
2118 static bool
dfs_find_final_overrider_1(tree binfo,find_final_overrider_data * ffod,unsigned depth)2119 dfs_find_final_overrider_1 (tree binfo,
2120 find_final_overrider_data *ffod,
2121 unsigned depth)
2122 {
2123 tree method;
2124
2125 /* If BINFO is not the most derived type, try a more derived class.
2126 A definition there will overrider a definition here. */
2127 if (depth)
2128 {
2129 depth--;
2130 if (dfs_find_final_overrider_1
2131 (ffod->path[depth], ffod, depth))
2132 return true;
2133 }
2134
2135 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
2136 if (method)
2137 {
2138 tree *candidate = &ffod->candidates;
2139
2140 /* Remove any candidates overridden by this new function. */
2141 while (*candidate)
2142 {
2143 /* If *CANDIDATE overrides METHOD, then METHOD
2144 cannot override anything else on the list. */
2145 if (base_derived_from (TREE_VALUE (*candidate), binfo))
2146 return true;
2147 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
2148 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
2149 *candidate = TREE_CHAIN (*candidate);
2150 else
2151 candidate = &TREE_CHAIN (*candidate);
2152 }
2153
2154 /* Add the new function. */
2155 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
2156 return true;
2157 }
2158
2159 return false;
2160 }
2161
2162 /* Called from find_final_overrider via dfs_walk. */
2163
2164 static tree
dfs_find_final_overrider_pre(tree binfo,void * data)2165 dfs_find_final_overrider_pre (tree binfo, void *data)
2166 {
2167 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
2168
2169 if (binfo == ffod->declaring_base)
2170 dfs_find_final_overrider_1 (binfo, ffod, ffod->path.length ());
2171 ffod->path.safe_push (binfo);
2172
2173 return NULL_TREE;
2174 }
2175
2176 static tree
dfs_find_final_overrider_post(tree,void * data)2177 dfs_find_final_overrider_post (tree /*binfo*/, void *data)
2178 {
2179 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
2180 ffod->path.pop ();
2181
2182 return NULL_TREE;
2183 }
2184
2185 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
2186 FN and whose TREE_VALUE is the binfo for the base where the
2187 overriding occurs. BINFO (in the hierarchy dominated by the binfo
2188 DERIVED) is the base object in which FN is declared. */
2189
2190 static tree
find_final_overrider(tree derived,tree binfo,tree fn)2191 find_final_overrider (tree derived, tree binfo, tree fn)
2192 {
2193 find_final_overrider_data ffod;
2194
2195 /* Getting this right is a little tricky. This is valid:
2196
2197 struct S { virtual void f (); };
2198 struct T { virtual void f (); };
2199 struct U : public S, public T { };
2200
2201 even though calling `f' in `U' is ambiguous. But,
2202
2203 struct R { virtual void f(); };
2204 struct S : virtual public R { virtual void f (); };
2205 struct T : virtual public R { virtual void f (); };
2206 struct U : public S, public T { };
2207
2208 is not -- there's no way to decide whether to put `S::f' or
2209 `T::f' in the vtable for `R'.
2210
2211 The solution is to look at all paths to BINFO. If we find
2212 different overriders along any two, then there is a problem. */
2213 if (DECL_THUNK_P (fn))
2214 fn = THUNK_TARGET (fn);
2215
2216 /* Determine the depth of the hierarchy. */
2217 ffod.fn = fn;
2218 ffod.declaring_base = binfo;
2219 ffod.candidates = NULL_TREE;
2220 ffod.path.create (30);
2221
2222 dfs_walk_all (derived, dfs_find_final_overrider_pre,
2223 dfs_find_final_overrider_post, &ffod);
2224
2225 ffod.path.release ();
2226
2227 /* If there was no winner, issue an error message. */
2228 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
2229 return error_mark_node;
2230
2231 return ffod.candidates;
2232 }
2233
2234 /* Return the index of the vcall offset for FN when TYPE is used as a
2235 virtual base. */
2236
2237 static tree
get_vcall_index(tree fn,tree type)2238 get_vcall_index (tree fn, tree type)
2239 {
2240 vec<tree_pair_s, va_gc> *indices = CLASSTYPE_VCALL_INDICES (type);
2241 tree_pair_p p;
2242 unsigned ix;
2243
2244 FOR_EACH_VEC_SAFE_ELT (indices, ix, p)
2245 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2246 || same_signature_p (fn, p->purpose))
2247 return p->value;
2248
2249 /* There should always be an appropriate index. */
2250 gcc_unreachable ();
2251 }
2252
2253 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2254 dominated by T. FN is the old function; VIRTUALS points to the
2255 corresponding position in the new BINFO_VIRTUALS list. IX is the index
2256 of that entry in the list. */
2257
2258 static void
update_vtable_entry_for_fn(tree t,tree binfo,tree fn,tree * virtuals,unsigned ix)2259 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2260 unsigned ix)
2261 {
2262 tree b;
2263 tree overrider;
2264 tree delta;
2265 tree virtual_base;
2266 tree first_defn;
2267 tree overrider_fn, overrider_target;
2268 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2269 tree over_return, base_return;
2270 bool lost = false;
2271
2272 /* Find the nearest primary base (possibly binfo itself) which defines
2273 this function; this is the class the caller will convert to when
2274 calling FN through BINFO. */
2275 for (b = binfo; ; b = get_primary_binfo (b))
2276 {
2277 gcc_assert (b);
2278 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2279 break;
2280
2281 /* The nearest definition is from a lost primary. */
2282 if (BINFO_LOST_PRIMARY_P (b))
2283 lost = true;
2284 }
2285 first_defn = b;
2286
2287 /* Find the final overrider. */
2288 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2289 if (overrider == error_mark_node)
2290 {
2291 error ("no unique final overrider for %qD in %qT", target_fn, t);
2292 return;
2293 }
2294 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2295
2296 /* Check for adjusting covariant return types. */
2297 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2298 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2299
2300 if (POINTER_TYPE_P (over_return)
2301 && TREE_CODE (over_return) == TREE_CODE (base_return)
2302 && CLASS_TYPE_P (TREE_TYPE (over_return))
2303 && CLASS_TYPE_P (TREE_TYPE (base_return))
2304 /* If the overrider is invalid, don't even try. */
2305 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2306 {
2307 /* If FN is a covariant thunk, we must figure out the adjustment
2308 to the final base FN was converting to. As OVERRIDER_TARGET might
2309 also be converting to the return type of FN, we have to
2310 combine the two conversions here. */
2311 tree fixed_offset, virtual_offset;
2312
2313 over_return = TREE_TYPE (over_return);
2314 base_return = TREE_TYPE (base_return);
2315
2316 if (DECL_THUNK_P (fn))
2317 {
2318 gcc_assert (DECL_RESULT_THUNK_P (fn));
2319 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2320 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2321 }
2322 else
2323 fixed_offset = virtual_offset = NULL_TREE;
2324
2325 if (virtual_offset)
2326 /* Find the equivalent binfo within the return type of the
2327 overriding function. We will want the vbase offset from
2328 there. */
2329 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2330 over_return);
2331 else if (!same_type_ignoring_top_level_qualifiers_p
2332 (over_return, base_return))
2333 {
2334 /* There was no existing virtual thunk (which takes
2335 precedence). So find the binfo of the base function's
2336 return type within the overriding function's return type.
2337 We cannot call lookup base here, because we're inside a
2338 dfs_walk, and will therefore clobber the BINFO_MARKED
2339 flags. Fortunately we know the covariancy is valid (it
2340 has already been checked), so we can just iterate along
2341 the binfos, which have been chained in inheritance graph
2342 order. Of course it is lame that we have to repeat the
2343 search here anyway -- we should really be caching pieces
2344 of the vtable and avoiding this repeated work. */
2345 tree thunk_binfo, base_binfo;
2346
2347 /* Find the base binfo within the overriding function's
2348 return type. We will always find a thunk_binfo, except
2349 when the covariancy is invalid (which we will have
2350 already diagnosed). */
2351 for (base_binfo = TYPE_BINFO (base_return),
2352 thunk_binfo = TYPE_BINFO (over_return);
2353 thunk_binfo;
2354 thunk_binfo = TREE_CHAIN (thunk_binfo))
2355 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2356 BINFO_TYPE (base_binfo)))
2357 break;
2358
2359 /* See if virtual inheritance is involved. */
2360 for (virtual_offset = thunk_binfo;
2361 virtual_offset;
2362 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2363 if (BINFO_VIRTUAL_P (virtual_offset))
2364 break;
2365
2366 if (virtual_offset
2367 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2368 {
2369 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2370
2371 if (virtual_offset)
2372 {
2373 /* We convert via virtual base. Adjust the fixed
2374 offset to be from there. */
2375 offset =
2376 size_diffop (offset,
2377 convert (ssizetype,
2378 BINFO_OFFSET (virtual_offset)));
2379 }
2380 if (fixed_offset)
2381 /* There was an existing fixed offset, this must be
2382 from the base just converted to, and the base the
2383 FN was thunking to. */
2384 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2385 else
2386 fixed_offset = offset;
2387 }
2388 }
2389
2390 if (fixed_offset || virtual_offset)
2391 /* Replace the overriding function with a covariant thunk. We
2392 will emit the overriding function in its own slot as
2393 well. */
2394 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2395 fixed_offset, virtual_offset);
2396 }
2397 else
2398 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) ||
2399 !DECL_THUNK_P (fn));
2400
2401 /* If we need a covariant thunk, then we may need to adjust first_defn.
2402 The ABI specifies that the thunks emitted with a function are
2403 determined by which bases the function overrides, so we need to be
2404 sure that we're using a thunk for some overridden base; even if we
2405 know that the necessary this adjustment is zero, there may not be an
2406 appropriate zero-this-adjusment thunk for us to use since thunks for
2407 overriding virtual bases always use the vcall offset.
2408
2409 Furthermore, just choosing any base that overrides this function isn't
2410 quite right, as this slot won't be used for calls through a type that
2411 puts a covariant thunk here. Calling the function through such a type
2412 will use a different slot, and that slot is the one that determines
2413 the thunk emitted for that base.
2414
2415 So, keep looking until we find the base that we're really overriding
2416 in this slot: the nearest primary base that doesn't use a covariant
2417 thunk in this slot. */
2418 if (overrider_target != overrider_fn)
2419 {
2420 if (BINFO_TYPE (b) == DECL_CONTEXT (overrider_target))
2421 /* We already know that the overrider needs a covariant thunk. */
2422 b = get_primary_binfo (b);
2423 for (; ; b = get_primary_binfo (b))
2424 {
2425 tree main_binfo = TYPE_BINFO (BINFO_TYPE (b));
2426 tree bv = chain_index (ix, BINFO_VIRTUALS (main_binfo));
2427 if (!DECL_THUNK_P (TREE_VALUE (bv)))
2428 break;
2429 if (BINFO_LOST_PRIMARY_P (b))
2430 lost = true;
2431 }
2432 first_defn = b;
2433 }
2434
2435 /* Assume that we will produce a thunk that convert all the way to
2436 the final overrider, and not to an intermediate virtual base. */
2437 virtual_base = NULL_TREE;
2438
2439 /* See if we can convert to an intermediate virtual base first, and then
2440 use the vcall offset located there to finish the conversion. */
2441 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2442 {
2443 /* If we find the final overrider, then we can stop
2444 walking. */
2445 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2446 BINFO_TYPE (TREE_VALUE (overrider))))
2447 break;
2448
2449 /* If we find a virtual base, and we haven't yet found the
2450 overrider, then there is a virtual base between the
2451 declaring base (first_defn) and the final overrider. */
2452 if (BINFO_VIRTUAL_P (b))
2453 {
2454 virtual_base = b;
2455 break;
2456 }
2457 }
2458
2459 /* Compute the constant adjustment to the `this' pointer. The
2460 `this' pointer, when this function is called, will point at BINFO
2461 (or one of its primary bases, which are at the same offset). */
2462 if (virtual_base)
2463 /* The `this' pointer needs to be adjusted from the declaration to
2464 the nearest virtual base. */
2465 delta = size_diffop_loc (input_location,
2466 convert (ssizetype, BINFO_OFFSET (virtual_base)),
2467 convert (ssizetype, BINFO_OFFSET (first_defn)));
2468 else if (lost)
2469 /* If the nearest definition is in a lost primary, we don't need an
2470 entry in our vtable. Except possibly in a constructor vtable,
2471 if we happen to get our primary back. In that case, the offset
2472 will be zero, as it will be a primary base. */
2473 delta = size_zero_node;
2474 else
2475 /* The `this' pointer needs to be adjusted from pointing to
2476 BINFO to pointing at the base where the final overrider
2477 appears. */
2478 delta = size_diffop_loc (input_location,
2479 convert (ssizetype,
2480 BINFO_OFFSET (TREE_VALUE (overrider))),
2481 convert (ssizetype, BINFO_OFFSET (binfo)));
2482
2483 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2484
2485 if (virtual_base)
2486 BV_VCALL_INDEX (*virtuals)
2487 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2488 else
2489 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2490
2491 BV_LOST_PRIMARY (*virtuals) = lost;
2492 }
2493
2494 /* Called from modify_all_vtables via dfs_walk. */
2495
2496 static tree
dfs_modify_vtables(tree binfo,void * data)2497 dfs_modify_vtables (tree binfo, void* data)
2498 {
2499 tree t = (tree) data;
2500 tree virtuals;
2501 tree old_virtuals;
2502 unsigned ix;
2503
2504 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2505 /* A base without a vtable needs no modification, and its bases
2506 are uninteresting. */
2507 return dfs_skip_bases;
2508
2509 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2510 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2511 /* Don't do the primary vtable, if it's new. */
2512 return NULL_TREE;
2513
2514 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2515 /* There's no need to modify the vtable for a non-virtual primary
2516 base; we're not going to use that vtable anyhow. We do still
2517 need to do this for virtual primary bases, as they could become
2518 non-primary in a construction vtable. */
2519 return NULL_TREE;
2520
2521 make_new_vtable (t, binfo);
2522
2523 /* Now, go through each of the virtual functions in the virtual
2524 function table for BINFO. Find the final overrider, and update
2525 the BINFO_VIRTUALS list appropriately. */
2526 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2527 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2528 virtuals;
2529 ix++, virtuals = TREE_CHAIN (virtuals),
2530 old_virtuals = TREE_CHAIN (old_virtuals))
2531 update_vtable_entry_for_fn (t,
2532 binfo,
2533 BV_FN (old_virtuals),
2534 &virtuals, ix);
2535
2536 return NULL_TREE;
2537 }
2538
2539 /* Update all of the primary and secondary vtables for T. Create new
2540 vtables as required, and initialize their RTTI information. Each
2541 of the functions in VIRTUALS is declared in T and may override a
2542 virtual function from a base class; find and modify the appropriate
2543 entries to point to the overriding functions. Returns a list, in
2544 declaration order, of the virtual functions that are declared in T,
2545 but do not appear in the primary base class vtable, and which
2546 should therefore be appended to the end of the vtable for T. */
2547
2548 static tree
modify_all_vtables(tree t,tree virtuals)2549 modify_all_vtables (tree t, tree virtuals)
2550 {
2551 tree binfo = TYPE_BINFO (t);
2552 tree *fnsp;
2553
2554 /* Mangle the vtable name before entering dfs_walk (c++/51884). */
2555 if (TYPE_CONTAINS_VPTR_P (t))
2556 get_vtable_decl (t, false);
2557
2558 /* Update all of the vtables. */
2559 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2560
2561 /* Add virtual functions not already in our primary vtable. These
2562 will be both those introduced by this class, and those overridden
2563 from secondary bases. It does not include virtuals merely
2564 inherited from secondary bases. */
2565 for (fnsp = &virtuals; *fnsp; )
2566 {
2567 tree fn = TREE_VALUE (*fnsp);
2568
2569 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2570 || DECL_VINDEX (fn) == error_mark_node)
2571 {
2572 /* We don't need to adjust the `this' pointer when
2573 calling this function. */
2574 BV_DELTA (*fnsp) = integer_zero_node;
2575 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2576
2577 /* This is a function not already in our vtable. Keep it. */
2578 fnsp = &TREE_CHAIN (*fnsp);
2579 }
2580 else
2581 /* We've already got an entry for this function. Skip it. */
2582 *fnsp = TREE_CHAIN (*fnsp);
2583 }
2584
2585 return virtuals;
2586 }
2587
2588 /* Get the base virtual function declarations in T that have the
2589 indicated NAME. */
2590
2591 static tree
get_basefndecls(tree name,tree t)2592 get_basefndecls (tree name, tree t)
2593 {
2594 tree methods;
2595 tree base_fndecls = NULL_TREE;
2596 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2597 int i;
2598
2599 /* Find virtual functions in T with the indicated NAME. */
2600 i = lookup_fnfields_1 (t, name);
2601 if (i != -1)
2602 for (methods = (*CLASSTYPE_METHOD_VEC (t))[i];
2603 methods;
2604 methods = OVL_NEXT (methods))
2605 {
2606 tree method = OVL_CURRENT (methods);
2607
2608 if (TREE_CODE (method) == FUNCTION_DECL
2609 && DECL_VINDEX (method))
2610 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2611 }
2612
2613 if (base_fndecls)
2614 return base_fndecls;
2615
2616 for (i = 0; i < n_baseclasses; i++)
2617 {
2618 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2619 base_fndecls = chainon (get_basefndecls (name, basetype),
2620 base_fndecls);
2621 }
2622
2623 return base_fndecls;
2624 }
2625
2626 /* If this declaration supersedes the declaration of
2627 a method declared virtual in the base class, then
2628 mark this field as being virtual as well. */
2629
2630 void
check_for_override(tree decl,tree ctype)2631 check_for_override (tree decl, tree ctype)
2632 {
2633 bool overrides_found = false;
2634 if (TREE_CODE (decl) == TEMPLATE_DECL)
2635 /* In [temp.mem] we have:
2636
2637 A specialization of a member function template does not
2638 override a virtual function from a base class. */
2639 return;
2640 if ((DECL_DESTRUCTOR_P (decl)
2641 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2642 || DECL_CONV_FN_P (decl))
2643 && look_for_overrides (ctype, decl)
2644 && !DECL_STATIC_FUNCTION_P (decl))
2645 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2646 the error_mark_node so that we know it is an overriding
2647 function. */
2648 {
2649 DECL_VINDEX (decl) = decl;
2650 overrides_found = true;
2651 }
2652
2653 if (DECL_VIRTUAL_P (decl))
2654 {
2655 if (!DECL_VINDEX (decl))
2656 DECL_VINDEX (decl) = error_mark_node;
2657 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2658 if (DECL_DESTRUCTOR_P (decl))
2659 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (ctype) = true;
2660 }
2661 else if (DECL_FINAL_P (decl))
2662 error ("%q+#D marked final, but is not virtual", decl);
2663 if (DECL_OVERRIDE_P (decl) && !overrides_found)
2664 error ("%q+#D marked override, but does not override", decl);
2665 }
2666
2667 /* Warn about hidden virtual functions that are not overridden in t.
2668 We know that constructors and destructors don't apply. */
2669
2670 static void
warn_hidden(tree t)2671 warn_hidden (tree t)
2672 {
2673 vec<tree, va_gc> *method_vec = CLASSTYPE_METHOD_VEC (t);
2674 tree fns;
2675 size_t i;
2676
2677 /* We go through each separately named virtual function. */
2678 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2679 vec_safe_iterate (method_vec, i, &fns);
2680 ++i)
2681 {
2682 tree fn;
2683 tree name;
2684 tree fndecl;
2685 tree base_fndecls;
2686 tree base_binfo;
2687 tree binfo;
2688 int j;
2689
2690 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2691 have the same name. Figure out what name that is. */
2692 name = DECL_NAME (OVL_CURRENT (fns));
2693 /* There are no possibly hidden functions yet. */
2694 base_fndecls = NULL_TREE;
2695 /* Iterate through all of the base classes looking for possibly
2696 hidden functions. */
2697 for (binfo = TYPE_BINFO (t), j = 0;
2698 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2699 {
2700 tree basetype = BINFO_TYPE (base_binfo);
2701 base_fndecls = chainon (get_basefndecls (name, basetype),
2702 base_fndecls);
2703 }
2704
2705 /* If there are no functions to hide, continue. */
2706 if (!base_fndecls)
2707 continue;
2708
2709 /* Remove any overridden functions. */
2710 for (fn = fns; fn; fn = OVL_NEXT (fn))
2711 {
2712 fndecl = OVL_CURRENT (fn);
2713 if (DECL_VINDEX (fndecl))
2714 {
2715 tree *prev = &base_fndecls;
2716
2717 while (*prev)
2718 /* If the method from the base class has the same
2719 signature as the method from the derived class, it
2720 has been overridden. */
2721 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2722 *prev = TREE_CHAIN (*prev);
2723 else
2724 prev = &TREE_CHAIN (*prev);
2725 }
2726 }
2727
2728 /* Now give a warning for all base functions without overriders,
2729 as they are hidden. */
2730 while (base_fndecls)
2731 {
2732 /* Here we know it is a hider, and no overrider exists. */
2733 warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls));
2734 warning (OPT_Woverloaded_virtual, " by %q+D", fns);
2735 base_fndecls = TREE_CHAIN (base_fndecls);
2736 }
2737 }
2738 }
2739
2740 /* Check for things that are invalid. There are probably plenty of other
2741 things we should check for also. */
2742
2743 static void
finish_struct_anon(tree t)2744 finish_struct_anon (tree t)
2745 {
2746 tree field;
2747
2748 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
2749 {
2750 if (TREE_STATIC (field))
2751 continue;
2752 if (TREE_CODE (field) != FIELD_DECL)
2753 continue;
2754
2755 if (DECL_NAME (field) == NULL_TREE
2756 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2757 {
2758 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
2759 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2760 for (; elt; elt = DECL_CHAIN (elt))
2761 {
2762 /* We're generally only interested in entities the user
2763 declared, but we also find nested classes by noticing
2764 the TYPE_DECL that we create implicitly. You're
2765 allowed to put one anonymous union inside another,
2766 though, so we explicitly tolerate that. We use
2767 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2768 we also allow unnamed types used for defining fields. */
2769 if (DECL_ARTIFICIAL (elt)
2770 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2771 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2772 continue;
2773
2774 if (TREE_CODE (elt) != FIELD_DECL)
2775 {
2776 if (is_union)
2777 permerror (input_location, "%q+#D invalid; an anonymous union can "
2778 "only have non-static data members", elt);
2779 else
2780 permerror (input_location, "%q+#D invalid; an anonymous struct can "
2781 "only have non-static data members", elt);
2782 continue;
2783 }
2784
2785 if (TREE_PRIVATE (elt))
2786 {
2787 if (is_union)
2788 permerror (input_location, "private member %q+#D in anonymous union", elt);
2789 else
2790 permerror (input_location, "private member %q+#D in anonymous struct", elt);
2791 }
2792 else if (TREE_PROTECTED (elt))
2793 {
2794 if (is_union)
2795 permerror (input_location, "protected member %q+#D in anonymous union", elt);
2796 else
2797 permerror (input_location, "protected member %q+#D in anonymous struct", elt);
2798 }
2799
2800 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2801 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2802 }
2803 }
2804 }
2805 }
2806
2807 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2808 will be used later during class template instantiation.
2809 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2810 a non-static member data (FIELD_DECL), a member function
2811 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2812 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2813 When FRIEND_P is nonzero, T is either a friend class
2814 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2815 (FUNCTION_DECL, TEMPLATE_DECL). */
2816
2817 void
maybe_add_class_template_decl_list(tree type,tree t,int friend_p)2818 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2819 {
2820 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2821 if (CLASSTYPE_TEMPLATE_INFO (type))
2822 CLASSTYPE_DECL_LIST (type)
2823 = tree_cons (friend_p ? NULL_TREE : type,
2824 t, CLASSTYPE_DECL_LIST (type));
2825 }
2826
2827 /* This function is called from declare_virt_assop_and_dtor via
2828 dfs_walk_all.
2829
2830 DATA is a type that direcly or indirectly inherits the base
2831 represented by BINFO. If BINFO contains a virtual assignment [copy
2832 assignment or move assigment] operator or a virtual constructor,
2833 declare that function in DATA if it hasn't been already declared. */
2834
2835 static tree
dfs_declare_virt_assop_and_dtor(tree binfo,void * data)2836 dfs_declare_virt_assop_and_dtor (tree binfo, void *data)
2837 {
2838 tree bv, fn, t = (tree)data;
2839 tree opname = ansi_assopname (NOP_EXPR);
2840
2841 gcc_assert (t && CLASS_TYPE_P (t));
2842 gcc_assert (binfo && TREE_CODE (binfo) == TREE_BINFO);
2843
2844 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2845 /* A base without a vtable needs no modification, and its bases
2846 are uninteresting. */
2847 return dfs_skip_bases;
2848
2849 if (BINFO_PRIMARY_P (binfo))
2850 /* If this is a primary base, then we have already looked at the
2851 virtual functions of its vtable. */
2852 return NULL_TREE;
2853
2854 for (bv = BINFO_VIRTUALS (binfo); bv; bv = TREE_CHAIN (bv))
2855 {
2856 fn = BV_FN (bv);
2857
2858 if (DECL_NAME (fn) == opname)
2859 {
2860 if (CLASSTYPE_LAZY_COPY_ASSIGN (t))
2861 lazily_declare_fn (sfk_copy_assignment, t);
2862 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t))
2863 lazily_declare_fn (sfk_move_assignment, t);
2864 }
2865 else if (DECL_DESTRUCTOR_P (fn)
2866 && CLASSTYPE_LAZY_DESTRUCTOR (t))
2867 lazily_declare_fn (sfk_destructor, t);
2868 }
2869
2870 return NULL_TREE;
2871 }
2872
2873 /* If the class type T has a direct or indirect base that contains a
2874 virtual assignment operator or a virtual destructor, declare that
2875 function in T if it hasn't been already declared. */
2876
2877 static void
declare_virt_assop_and_dtor(tree t)2878 declare_virt_assop_and_dtor (tree t)
2879 {
2880 if (!(TYPE_POLYMORPHIC_P (t)
2881 && (CLASSTYPE_LAZY_COPY_ASSIGN (t)
2882 || CLASSTYPE_LAZY_MOVE_ASSIGN (t)
2883 || CLASSTYPE_LAZY_DESTRUCTOR (t))))
2884 return;
2885
2886 dfs_walk_all (TYPE_BINFO (t),
2887 dfs_declare_virt_assop_and_dtor,
2888 NULL, t);
2889 }
2890
2891 /* Declare the inheriting constructor for class T inherited from base
2892 constructor CTOR with the parameter array PARMS of size NPARMS. */
2893
2894 static void
one_inheriting_sig(tree t,tree ctor,tree * parms,int nparms)2895 one_inheriting_sig (tree t, tree ctor, tree *parms, int nparms)
2896 {
2897 /* We don't declare an inheriting ctor that would be a default,
2898 copy or move ctor for derived or base. */
2899 if (nparms == 0)
2900 return;
2901 if (nparms == 1
2902 && TREE_CODE (parms[0]) == REFERENCE_TYPE)
2903 {
2904 tree parm = TYPE_MAIN_VARIANT (TREE_TYPE (parms[0]));
2905 if (parm == t || parm == DECL_CONTEXT (ctor))
2906 return;
2907 }
2908
2909 tree parmlist = void_list_node;
2910 for (int i = nparms - 1; i >= 0; i--)
2911 parmlist = tree_cons (NULL_TREE, parms[i], parmlist);
2912 tree fn = implicitly_declare_fn (sfk_inheriting_constructor,
2913 t, false, ctor, parmlist);
2914 if (add_method (t, fn, NULL_TREE))
2915 {
2916 DECL_CHAIN (fn) = TYPE_METHODS (t);
2917 TYPE_METHODS (t) = fn;
2918 }
2919 }
2920
2921 /* Declare all the inheriting constructors for class T inherited from base
2922 constructor CTOR. */
2923
2924 static void
one_inherited_ctor(tree ctor,tree t)2925 one_inherited_ctor (tree ctor, tree t)
2926 {
2927 tree parms = FUNCTION_FIRST_USER_PARMTYPE (ctor);
2928
2929 tree *new_parms = XALLOCAVEC (tree, list_length (parms));
2930 int i = 0;
2931 for (; parms && parms != void_list_node; parms = TREE_CHAIN (parms))
2932 {
2933 if (TREE_PURPOSE (parms))
2934 one_inheriting_sig (t, ctor, new_parms, i);
2935 new_parms[i++] = TREE_VALUE (parms);
2936 }
2937 one_inheriting_sig (t, ctor, new_parms, i);
2938 if (parms == NULL_TREE)
2939 {
2940 warning (OPT_Winherited_variadic_ctor,
2941 "the ellipsis in %qD is not inherited", ctor);
2942 inform (DECL_SOURCE_LOCATION (ctor), "%qD declared here", ctor);
2943 }
2944 }
2945
2946 /* Create default constructors, assignment operators, and so forth for
2947 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2948 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2949 the class cannot have a default constructor, copy constructor
2950 taking a const reference argument, or an assignment operator taking
2951 a const reference, respectively. */
2952
2953 static void
add_implicitly_declared_members(tree t,tree * access_decls,int cant_have_const_cctor,int cant_have_const_assignment)2954 add_implicitly_declared_members (tree t, tree* access_decls,
2955 int cant_have_const_cctor,
2956 int cant_have_const_assignment)
2957 {
2958 bool move_ok = false;
2959
2960 if (cxx_dialect >= cxx0x && !CLASSTYPE_DESTRUCTORS (t)
2961 && !TYPE_HAS_COPY_CTOR (t) && !TYPE_HAS_COPY_ASSIGN (t)
2962 && !type_has_move_constructor (t) && !type_has_move_assign (t))
2963 move_ok = true;
2964
2965 /* Destructor. */
2966 if (!CLASSTYPE_DESTRUCTORS (t))
2967 {
2968 /* In general, we create destructors lazily. */
2969 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2970
2971 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2972 && TYPE_FOR_JAVA (t))
2973 /* But if this is a Java class, any non-trivial destructor is
2974 invalid, even if compiler-generated. Therefore, if the
2975 destructor is non-trivial we create it now. */
2976 lazily_declare_fn (sfk_destructor, t);
2977 }
2978
2979 /* [class.ctor]
2980
2981 If there is no user-declared constructor for a class, a default
2982 constructor is implicitly declared. */
2983 if (! TYPE_HAS_USER_CONSTRUCTOR (t))
2984 {
2985 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2986 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2987 if (cxx_dialect >= cxx0x)
2988 TYPE_HAS_CONSTEXPR_CTOR (t)
2989 /* This might force the declaration. */
2990 = type_has_constexpr_default_constructor (t);
2991 }
2992
2993 /* [class.ctor]
2994
2995 If a class definition does not explicitly declare a copy
2996 constructor, one is declared implicitly. */
2997 if (! TYPE_HAS_COPY_CTOR (t) && ! TYPE_FOR_JAVA (t))
2998 {
2999 TYPE_HAS_COPY_CTOR (t) = 1;
3000 TYPE_HAS_CONST_COPY_CTOR (t) = !cant_have_const_cctor;
3001 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
3002 if (move_ok)
3003 CLASSTYPE_LAZY_MOVE_CTOR (t) = 1;
3004 }
3005
3006 /* If there is no assignment operator, one will be created if and
3007 when it is needed. For now, just record whether or not the type
3008 of the parameter to the assignment operator will be a const or
3009 non-const reference. */
3010 if (!TYPE_HAS_COPY_ASSIGN (t) && !TYPE_FOR_JAVA (t))
3011 {
3012 TYPE_HAS_COPY_ASSIGN (t) = 1;
3013 TYPE_HAS_CONST_COPY_ASSIGN (t) = !cant_have_const_assignment;
3014 CLASSTYPE_LAZY_COPY_ASSIGN (t) = 1;
3015 if (move_ok)
3016 CLASSTYPE_LAZY_MOVE_ASSIGN (t) = 1;
3017 }
3018
3019 /* We can't be lazy about declaring functions that might override
3020 a virtual function from a base class. */
3021 declare_virt_assop_and_dtor (t);
3022
3023 while (*access_decls)
3024 {
3025 tree using_decl = TREE_VALUE (*access_decls);
3026 tree decl = USING_DECL_DECLS (using_decl);
3027 if (DECL_NAME (using_decl) == ctor_identifier)
3028 {
3029 /* declare, then remove the decl */
3030 tree ctor_list = decl;
3031 location_t loc = input_location;
3032 input_location = DECL_SOURCE_LOCATION (using_decl);
3033 if (ctor_list)
3034 for (; ctor_list; ctor_list = OVL_NEXT (ctor_list))
3035 one_inherited_ctor (OVL_CURRENT (ctor_list), t);
3036 *access_decls = TREE_CHAIN (*access_decls);
3037 input_location = loc;
3038 }
3039 else
3040 access_decls = &TREE_CHAIN (*access_decls);
3041 }
3042 }
3043
3044 /* Subroutine of insert_into_classtype_sorted_fields. Recursively
3045 count the number of fields in TYPE, including anonymous union
3046 members. */
3047
3048 static int
count_fields(tree fields)3049 count_fields (tree fields)
3050 {
3051 tree x;
3052 int n_fields = 0;
3053 for (x = fields; x; x = DECL_CHAIN (x))
3054 {
3055 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
3056 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
3057 else
3058 n_fields += 1;
3059 }
3060 return n_fields;
3061 }
3062
3063 /* Subroutine of insert_into_classtype_sorted_fields. Recursively add
3064 all the fields in the TREE_LIST FIELDS to the SORTED_FIELDS_TYPE
3065 elts, starting at offset IDX. */
3066
3067 static int
add_fields_to_record_type(tree fields,struct sorted_fields_type * field_vec,int idx)3068 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
3069 {
3070 tree x;
3071 for (x = fields; x; x = DECL_CHAIN (x))
3072 {
3073 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
3074 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
3075 else
3076 field_vec->elts[idx++] = x;
3077 }
3078 return idx;
3079 }
3080
3081 /* Add all of the enum values of ENUMTYPE, to the FIELD_VEC elts,
3082 starting at offset IDX. */
3083
3084 static int
add_enum_fields_to_record_type(tree enumtype,struct sorted_fields_type * field_vec,int idx)3085 add_enum_fields_to_record_type (tree enumtype,
3086 struct sorted_fields_type *field_vec,
3087 int idx)
3088 {
3089 tree values;
3090 for (values = TYPE_VALUES (enumtype); values; values = TREE_CHAIN (values))
3091 field_vec->elts[idx++] = TREE_VALUE (values);
3092 return idx;
3093 }
3094
3095 /* FIELD is a bit-field. We are finishing the processing for its
3096 enclosing type. Issue any appropriate messages and set appropriate
3097 flags. Returns false if an error has been diagnosed. */
3098
3099 static bool
check_bitfield_decl(tree field)3100 check_bitfield_decl (tree field)
3101 {
3102 tree type = TREE_TYPE (field);
3103 tree w;
3104
3105 /* Extract the declared width of the bitfield, which has been
3106 temporarily stashed in DECL_INITIAL. */
3107 w = DECL_INITIAL (field);
3108 gcc_assert (w != NULL_TREE);
3109 /* Remove the bit-field width indicator so that the rest of the
3110 compiler does not treat that value as an initializer. */
3111 DECL_INITIAL (field) = NULL_TREE;
3112
3113 /* Detect invalid bit-field type. */
3114 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type))
3115 {
3116 error ("bit-field %q+#D with non-integral type", field);
3117 w = error_mark_node;
3118 }
3119 else
3120 {
3121 location_t loc = input_location;
3122 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
3123 STRIP_NOPS (w);
3124
3125 /* detect invalid field size. */
3126 input_location = DECL_SOURCE_LOCATION (field);
3127 w = cxx_constant_value (w);
3128 input_location = loc;
3129
3130 if (TREE_CODE (w) != INTEGER_CST)
3131 {
3132 error ("bit-field %q+D width not an integer constant", field);
3133 w = error_mark_node;
3134 }
3135 else if (tree_int_cst_sgn (w) < 0)
3136 {
3137 error ("negative width in bit-field %q+D", field);
3138 w = error_mark_node;
3139 }
3140 else if (integer_zerop (w) && DECL_NAME (field) != 0)
3141 {
3142 error ("zero width for bit-field %q+D", field);
3143 w = error_mark_node;
3144 }
3145 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
3146 && TREE_CODE (type) != ENUMERAL_TYPE
3147 && TREE_CODE (type) != BOOLEAN_TYPE)
3148 warning (0, "width of %q+D exceeds its type", field);
3149 else if (TREE_CODE (type) == ENUMERAL_TYPE
3150 && (0 > (compare_tree_int
3151 (w, TYPE_PRECISION (ENUM_UNDERLYING_TYPE (type))))))
3152 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
3153 }
3154
3155 if (w != error_mark_node)
3156 {
3157 DECL_SIZE (field) = convert (bitsizetype, w);
3158 DECL_BIT_FIELD (field) = 1;
3159 return true;
3160 }
3161 else
3162 {
3163 /* Non-bit-fields are aligned for their type. */
3164 DECL_BIT_FIELD (field) = 0;
3165 CLEAR_DECL_C_BIT_FIELD (field);
3166 return false;
3167 }
3168 }
3169
3170 /* FIELD is a non bit-field. We are finishing the processing for its
3171 enclosing type T. Issue any appropriate messages and set appropriate
3172 flags. */
3173
3174 static void
check_field_decl(tree field,tree t,int * cant_have_const_ctor,int * no_const_asn_ref,int * any_default_members)3175 check_field_decl (tree field,
3176 tree t,
3177 int* cant_have_const_ctor,
3178 int* no_const_asn_ref,
3179 int* any_default_members)
3180 {
3181 tree type = strip_array_types (TREE_TYPE (field));
3182
3183 /* In C++98 an anonymous union cannot contain any fields which would change
3184 the settings of CANT_HAVE_CONST_CTOR and friends. */
3185 if (ANON_UNION_TYPE_P (type) && cxx_dialect < cxx0x)
3186 ;
3187 /* And, we don't set TYPE_HAS_CONST_COPY_CTOR, etc., for anonymous
3188 structs. So, we recurse through their fields here. */
3189 else if (ANON_AGGR_TYPE_P (type))
3190 {
3191 tree fields;
3192
3193 for (fields = TYPE_FIELDS (type); fields; fields = DECL_CHAIN (fields))
3194 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
3195 check_field_decl (fields, t, cant_have_const_ctor,
3196 no_const_asn_ref, any_default_members);
3197 }
3198 /* Check members with class type for constructors, destructors,
3199 etc. */
3200 else if (CLASS_TYPE_P (type))
3201 {
3202 /* Never let anything with uninheritable virtuals
3203 make it through without complaint. */
3204 abstract_virtuals_error (field, type);
3205
3206 if (TREE_CODE (t) == UNION_TYPE && cxx_dialect < cxx0x)
3207 {
3208 static bool warned;
3209 int oldcount = errorcount;
3210 if (TYPE_NEEDS_CONSTRUCTING (type))
3211 error ("member %q+#D with constructor not allowed in union",
3212 field);
3213 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3214 error ("member %q+#D with destructor not allowed in union", field);
3215 if (TYPE_HAS_COMPLEX_COPY_ASSIGN (type))
3216 error ("member %q+#D with copy assignment operator not allowed in union",
3217 field);
3218 if (!warned && errorcount > oldcount)
3219 {
3220 inform (DECL_SOURCE_LOCATION (field), "unrestricted unions "
3221 "only available with -std=c++11 or -std=gnu++11");
3222 warned = true;
3223 }
3224 }
3225 else
3226 {
3227 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
3228 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3229 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
3230 TYPE_HAS_COMPLEX_COPY_ASSIGN (t)
3231 |= (TYPE_HAS_COMPLEX_COPY_ASSIGN (type)
3232 || !TYPE_HAS_COPY_ASSIGN (type));
3233 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= (TYPE_HAS_COMPLEX_COPY_CTOR (type)
3234 || !TYPE_HAS_COPY_CTOR (type));
3235 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_HAS_COMPLEX_MOVE_ASSIGN (type);
3236 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_HAS_COMPLEX_MOVE_CTOR (type);
3237 TYPE_HAS_COMPLEX_DFLT (t) |= (!TYPE_HAS_DEFAULT_CONSTRUCTOR (type)
3238 || TYPE_HAS_COMPLEX_DFLT (type));
3239 }
3240
3241 if (TYPE_HAS_COPY_CTOR (type)
3242 && !TYPE_HAS_CONST_COPY_CTOR (type))
3243 *cant_have_const_ctor = 1;
3244
3245 if (TYPE_HAS_COPY_ASSIGN (type)
3246 && !TYPE_HAS_CONST_COPY_ASSIGN (type))
3247 *no_const_asn_ref = 1;
3248 }
3249
3250 check_abi_tags (t, field);
3251
3252 if (DECL_INITIAL (field) != NULL_TREE)
3253 {
3254 /* `build_class_init_list' does not recognize
3255 non-FIELD_DECLs. */
3256 if (TREE_CODE (t) == UNION_TYPE && *any_default_members != 0)
3257 error ("multiple fields in union %qT initialized", t);
3258 *any_default_members = 1;
3259 }
3260 }
3261
3262 /* Check the data members (both static and non-static), class-scoped
3263 typedefs, etc., appearing in the declaration of T. Issue
3264 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
3265 declaration order) of access declarations; each TREE_VALUE in this
3266 list is a USING_DECL.
3267
3268 In addition, set the following flags:
3269
3270 EMPTY_P
3271 The class is empty, i.e., contains no non-static data members.
3272
3273 CANT_HAVE_CONST_CTOR_P
3274 This class cannot have an implicitly generated copy constructor
3275 taking a const reference.
3276
3277 CANT_HAVE_CONST_ASN_REF
3278 This class cannot have an implicitly generated assignment
3279 operator taking a const reference.
3280
3281 All of these flags should be initialized before calling this
3282 function.
3283
3284 Returns a pointer to the end of the TYPE_FIELDs chain; additional
3285 fields can be added by adding to this chain. */
3286
3287 static void
check_field_decls(tree t,tree * access_decls,int * cant_have_const_ctor_p,int * no_const_asn_ref_p)3288 check_field_decls (tree t, tree *access_decls,
3289 int *cant_have_const_ctor_p,
3290 int *no_const_asn_ref_p)
3291 {
3292 tree *field;
3293 tree *next;
3294 bool has_pointers;
3295 int any_default_members;
3296 int cant_pack = 0;
3297 int field_access = -1;
3298
3299 /* Assume there are no access declarations. */
3300 *access_decls = NULL_TREE;
3301 /* Assume this class has no pointer members. */
3302 has_pointers = false;
3303 /* Assume none of the members of this class have default
3304 initializations. */
3305 any_default_members = 0;
3306
3307 for (field = &TYPE_FIELDS (t); *field; field = next)
3308 {
3309 tree x = *field;
3310 tree type = TREE_TYPE (x);
3311 int this_field_access;
3312
3313 next = &DECL_CHAIN (x);
3314
3315 if (TREE_CODE (x) == USING_DECL)
3316 {
3317 /* Save the access declarations for our caller. */
3318 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
3319 continue;
3320 }
3321
3322 if (TREE_CODE (x) == TYPE_DECL
3323 || TREE_CODE (x) == TEMPLATE_DECL)
3324 continue;
3325
3326 /* If we've gotten this far, it's a data member, possibly static,
3327 or an enumerator. */
3328 if (TREE_CODE (x) != CONST_DECL)
3329 DECL_CONTEXT (x) = t;
3330
3331 /* When this goes into scope, it will be a non-local reference. */
3332 DECL_NONLOCAL (x) = 1;
3333
3334 if (TREE_CODE (t) == UNION_TYPE)
3335 {
3336 /* [class.union]
3337
3338 If a union contains a static data member, or a member of
3339 reference type, the program is ill-formed. */
3340 if (TREE_CODE (x) == VAR_DECL)
3341 {
3342 error ("%q+D may not be static because it is a member of a union", x);
3343 continue;
3344 }
3345 if (TREE_CODE (type) == REFERENCE_TYPE)
3346 {
3347 error ("%q+D may not have reference type %qT because"
3348 " it is a member of a union",
3349 x, type);
3350 continue;
3351 }
3352 }
3353
3354 /* Perform error checking that did not get done in
3355 grokdeclarator. */
3356 if (TREE_CODE (type) == FUNCTION_TYPE)
3357 {
3358 error ("field %q+D invalidly declared function type", x);
3359 type = build_pointer_type (type);
3360 TREE_TYPE (x) = type;
3361 }
3362 else if (TREE_CODE (type) == METHOD_TYPE)
3363 {
3364 error ("field %q+D invalidly declared method type", x);
3365 type = build_pointer_type (type);
3366 TREE_TYPE (x) = type;
3367 }
3368
3369 if (type == error_mark_node)
3370 continue;
3371
3372 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
3373 continue;
3374
3375 /* Now it can only be a FIELD_DECL. */
3376
3377 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
3378 CLASSTYPE_NON_AGGREGATE (t) = 1;
3379
3380 /* If at least one non-static data member is non-literal, the whole
3381 class becomes non-literal. Note: if the type is incomplete we
3382 will complain later on. */
3383 if (COMPLETE_TYPE_P (type) && !literal_type_p (type))
3384 CLASSTYPE_LITERAL_P (t) = false;
3385
3386 /* A standard-layout class is a class that:
3387 ...
3388 has the same access control (Clause 11) for all non-static data members,
3389 ... */
3390 this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0;
3391 if (field_access == -1)
3392 field_access = this_field_access;
3393 else if (this_field_access != field_access)
3394 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3395
3396 /* If this is of reference type, check if it needs an init. */
3397 if (TREE_CODE (type) == REFERENCE_TYPE)
3398 {
3399 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1;
3400 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3401 if (DECL_INITIAL (x) == NULL_TREE)
3402 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3403
3404 /* ARM $12.6.2: [A member initializer list] (or, for an
3405 aggregate, initialization by a brace-enclosed list) is the
3406 only way to initialize nonstatic const and reference
3407 members. */
3408 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1;
3409 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1;
3410 }
3411
3412 type = strip_array_types (type);
3413
3414 if (TYPE_PACKED (t))
3415 {
3416 if (!layout_pod_type_p (type) && !TYPE_PACKED (type))
3417 {
3418 warning
3419 (0,
3420 "ignoring packed attribute because of unpacked non-POD field %q+#D",
3421 x);
3422 cant_pack = 1;
3423 }
3424 else if (DECL_C_BIT_FIELD (x)
3425 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
3426 DECL_PACKED (x) = 1;
3427 }
3428
3429 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
3430 /* We don't treat zero-width bitfields as making a class
3431 non-empty. */
3432 ;
3433 else
3434 {
3435 /* The class is non-empty. */
3436 CLASSTYPE_EMPTY_P (t) = 0;
3437 /* The class is not even nearly empty. */
3438 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3439 /* If one of the data members contains an empty class,
3440 so does T. */
3441 if (CLASS_TYPE_P (type)
3442 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3443 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
3444 }
3445
3446 /* This is used by -Weffc++ (see below). Warn only for pointers
3447 to members which might hold dynamic memory. So do not warn
3448 for pointers to functions or pointers to members. */
3449 if (TYPE_PTR_P (type)
3450 && !TYPE_PTRFN_P (type))
3451 has_pointers = true;
3452
3453 if (CLASS_TYPE_P (type))
3454 {
3455 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3456 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3457 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3458 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3459 }
3460
3461 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3462 CLASSTYPE_HAS_MUTABLE (t) = 1;
3463
3464 if (! layout_pod_type_p (type))
3465 /* DR 148 now allows pointers to members (which are POD themselves),
3466 to be allowed in POD structs. */
3467 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1;
3468
3469 if (!std_layout_type_p (type))
3470 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3471
3472 if (! zero_init_p (type))
3473 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3474
3475 /* We set DECL_C_BIT_FIELD in grokbitfield.
3476 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3477 if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x))
3478 check_field_decl (x, t,
3479 cant_have_const_ctor_p,
3480 no_const_asn_ref_p,
3481 &any_default_members);
3482
3483 /* Now that we've removed bit-field widths from DECL_INITIAL,
3484 anything left in DECL_INITIAL is an NSDMI that makes the class
3485 non-aggregate. */
3486 if (DECL_INITIAL (x))
3487 CLASSTYPE_NON_AGGREGATE (t) = true;
3488
3489 /* If any field is const, the structure type is pseudo-const. */
3490 if (CP_TYPE_CONST_P (type))
3491 {
3492 C_TYPE_FIELDS_READONLY (t) = 1;
3493 if (DECL_INITIAL (x) == NULL_TREE)
3494 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3495
3496 /* ARM $12.6.2: [A member initializer list] (or, for an
3497 aggregate, initialization by a brace-enclosed list) is the
3498 only way to initialize nonstatic const and reference
3499 members. */
3500 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1;
3501 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) = 1;
3502 }
3503 /* A field that is pseudo-const makes the structure likewise. */
3504 else if (CLASS_TYPE_P (type))
3505 {
3506 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3507 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3508 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3509 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3510 }
3511
3512 /* Core issue 80: A nonstatic data member is required to have a
3513 different name from the class iff the class has a
3514 user-declared constructor. */
3515 if (constructor_name_p (DECL_NAME (x), t)
3516 && TYPE_HAS_USER_CONSTRUCTOR (t))
3517 permerror (input_location, "field %q+#D with same name as class", x);
3518 }
3519
3520 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3521 it should also define a copy constructor and an assignment operator to
3522 implement the correct copy semantic (deep vs shallow, etc.). As it is
3523 not feasible to check whether the constructors do allocate dynamic memory
3524 and store it within members, we approximate the warning like this:
3525
3526 -- Warn only if there are members which are pointers
3527 -- Warn only if there is a non-trivial constructor (otherwise,
3528 there cannot be memory allocated).
3529 -- Warn only if there is a non-trivial destructor. We assume that the
3530 user at least implemented the cleanup correctly, and a destructor
3531 is needed to free dynamic memory.
3532
3533 This seems enough for practical purposes. */
3534 if (warn_ecpp
3535 && has_pointers
3536 && TYPE_HAS_USER_CONSTRUCTOR (t)
3537 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3538 && !(TYPE_HAS_COPY_CTOR (t) && TYPE_HAS_COPY_ASSIGN (t)))
3539 {
3540 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3541
3542 if (! TYPE_HAS_COPY_CTOR (t))
3543 {
3544 warning (OPT_Weffc__,
3545 " but does not override %<%T(const %T&)%>", t, t);
3546 if (!TYPE_HAS_COPY_ASSIGN (t))
3547 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3548 }
3549 else if (! TYPE_HAS_COPY_ASSIGN (t))
3550 warning (OPT_Weffc__,
3551 " but does not override %<operator=(const %T&)%>", t);
3552 }
3553
3554 /* Non-static data member initializers make the default constructor
3555 non-trivial. */
3556 if (any_default_members)
3557 {
3558 TYPE_NEEDS_CONSTRUCTING (t) = true;
3559 TYPE_HAS_COMPLEX_DFLT (t) = true;
3560 }
3561
3562 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3563 if (cant_pack)
3564 TYPE_PACKED (t) = 0;
3565
3566 /* Check anonymous struct/anonymous union fields. */
3567 finish_struct_anon (t);
3568
3569 /* We've built up the list of access declarations in reverse order.
3570 Fix that now. */
3571 *access_decls = nreverse (*access_decls);
3572 }
3573
3574 /* If TYPE is an empty class type, records its OFFSET in the table of
3575 OFFSETS. */
3576
3577 static int
record_subobject_offset(tree type,tree offset,splay_tree offsets)3578 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3579 {
3580 splay_tree_node n;
3581
3582 if (!is_empty_class (type))
3583 return 0;
3584
3585 /* Record the location of this empty object in OFFSETS. */
3586 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3587 if (!n)
3588 n = splay_tree_insert (offsets,
3589 (splay_tree_key) offset,
3590 (splay_tree_value) NULL_TREE);
3591 n->value = ((splay_tree_value)
3592 tree_cons (NULL_TREE,
3593 type,
3594 (tree) n->value));
3595
3596 return 0;
3597 }
3598
3599 /* Returns nonzero if TYPE is an empty class type and there is
3600 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3601
3602 static int
check_subobject_offset(tree type,tree offset,splay_tree offsets)3603 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3604 {
3605 splay_tree_node n;
3606 tree t;
3607
3608 if (!is_empty_class (type))
3609 return 0;
3610
3611 /* Record the location of this empty object in OFFSETS. */
3612 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3613 if (!n)
3614 return 0;
3615
3616 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3617 if (same_type_p (TREE_VALUE (t), type))
3618 return 1;
3619
3620 return 0;
3621 }
3622
3623 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3624 F for every subobject, passing it the type, offset, and table of
3625 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3626 be traversed.
3627
3628 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3629 than MAX_OFFSET will not be walked.
3630
3631 If F returns a nonzero value, the traversal ceases, and that value
3632 is returned. Otherwise, returns zero. */
3633
3634 static int
walk_subobject_offsets(tree type,subobject_offset_fn f,tree offset,splay_tree offsets,tree max_offset,int vbases_p)3635 walk_subobject_offsets (tree type,
3636 subobject_offset_fn f,
3637 tree offset,
3638 splay_tree offsets,
3639 tree max_offset,
3640 int vbases_p)
3641 {
3642 int r = 0;
3643 tree type_binfo = NULL_TREE;
3644
3645 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3646 stop. */
3647 if (max_offset && INT_CST_LT (max_offset, offset))
3648 return 0;
3649
3650 if (type == error_mark_node)
3651 return 0;
3652
3653 if (!TYPE_P (type))
3654 {
3655 if (abi_version_at_least (2))
3656 type_binfo = type;
3657 type = BINFO_TYPE (type);
3658 }
3659
3660 if (CLASS_TYPE_P (type))
3661 {
3662 tree field;
3663 tree binfo;
3664 int i;
3665
3666 /* Avoid recursing into objects that are not interesting. */
3667 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3668 return 0;
3669
3670 /* Record the location of TYPE. */
3671 r = (*f) (type, offset, offsets);
3672 if (r)
3673 return r;
3674
3675 /* Iterate through the direct base classes of TYPE. */
3676 if (!type_binfo)
3677 type_binfo = TYPE_BINFO (type);
3678 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3679 {
3680 tree binfo_offset;
3681
3682 if (abi_version_at_least (2)
3683 && BINFO_VIRTUAL_P (binfo))
3684 continue;
3685
3686 if (!vbases_p
3687 && BINFO_VIRTUAL_P (binfo)
3688 && !BINFO_PRIMARY_P (binfo))
3689 continue;
3690
3691 if (!abi_version_at_least (2))
3692 binfo_offset = size_binop (PLUS_EXPR,
3693 offset,
3694 BINFO_OFFSET (binfo));
3695 else
3696 {
3697 tree orig_binfo;
3698 /* We cannot rely on BINFO_OFFSET being set for the base
3699 class yet, but the offsets for direct non-virtual
3700 bases can be calculated by going back to the TYPE. */
3701 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3702 binfo_offset = size_binop (PLUS_EXPR,
3703 offset,
3704 BINFO_OFFSET (orig_binfo));
3705 }
3706
3707 r = walk_subobject_offsets (binfo,
3708 f,
3709 binfo_offset,
3710 offsets,
3711 max_offset,
3712 (abi_version_at_least (2)
3713 ? /*vbases_p=*/0 : vbases_p));
3714 if (r)
3715 return r;
3716 }
3717
3718 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3719 {
3720 unsigned ix;
3721 vec<tree, va_gc> *vbases;
3722
3723 /* Iterate through the virtual base classes of TYPE. In G++
3724 3.2, we included virtual bases in the direct base class
3725 loop above, which results in incorrect results; the
3726 correct offsets for virtual bases are only known when
3727 working with the most derived type. */
3728 if (vbases_p)
3729 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3730 vec_safe_iterate (vbases, ix, &binfo); ix++)
3731 {
3732 r = walk_subobject_offsets (binfo,
3733 f,
3734 size_binop (PLUS_EXPR,
3735 offset,
3736 BINFO_OFFSET (binfo)),
3737 offsets,
3738 max_offset,
3739 /*vbases_p=*/0);
3740 if (r)
3741 return r;
3742 }
3743 else
3744 {
3745 /* We still have to walk the primary base, if it is
3746 virtual. (If it is non-virtual, then it was walked
3747 above.) */
3748 tree vbase = get_primary_binfo (type_binfo);
3749
3750 if (vbase && BINFO_VIRTUAL_P (vbase)
3751 && BINFO_PRIMARY_P (vbase)
3752 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3753 {
3754 r = (walk_subobject_offsets
3755 (vbase, f, offset,
3756 offsets, max_offset, /*vbases_p=*/0));
3757 if (r)
3758 return r;
3759 }
3760 }
3761 }
3762
3763 /* Iterate through the fields of TYPE. */
3764 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
3765 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3766 {
3767 tree field_offset;
3768
3769 if (abi_version_at_least (2))
3770 field_offset = byte_position (field);
3771 else
3772 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3773 field_offset = DECL_FIELD_OFFSET (field);
3774
3775 r = walk_subobject_offsets (TREE_TYPE (field),
3776 f,
3777 size_binop (PLUS_EXPR,
3778 offset,
3779 field_offset),
3780 offsets,
3781 max_offset,
3782 /*vbases_p=*/1);
3783 if (r)
3784 return r;
3785 }
3786 }
3787 else if (TREE_CODE (type) == ARRAY_TYPE)
3788 {
3789 tree element_type = strip_array_types (type);
3790 tree domain = TYPE_DOMAIN (type);
3791 tree index;
3792
3793 /* Avoid recursing into objects that are not interesting. */
3794 if (!CLASS_TYPE_P (element_type)
3795 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3796 return 0;
3797
3798 /* Step through each of the elements in the array. */
3799 for (index = size_zero_node;
3800 /* G++ 3.2 had an off-by-one error here. */
3801 (abi_version_at_least (2)
3802 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3803 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3804 index = size_binop (PLUS_EXPR, index, size_one_node))
3805 {
3806 r = walk_subobject_offsets (TREE_TYPE (type),
3807 f,
3808 offset,
3809 offsets,
3810 max_offset,
3811 /*vbases_p=*/1);
3812 if (r)
3813 return r;
3814 offset = size_binop (PLUS_EXPR, offset,
3815 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3816 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3817 there's no point in iterating through the remaining
3818 elements of the array. */
3819 if (max_offset && INT_CST_LT (max_offset, offset))
3820 break;
3821 }
3822 }
3823
3824 return 0;
3825 }
3826
3827 /* Record all of the empty subobjects of TYPE (either a type or a
3828 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3829 is being placed at OFFSET; otherwise, it is a base class that is
3830 being placed at OFFSET. */
3831
3832 static void
record_subobject_offsets(tree type,tree offset,splay_tree offsets,bool is_data_member)3833 record_subobject_offsets (tree type,
3834 tree offset,
3835 splay_tree offsets,
3836 bool is_data_member)
3837 {
3838 tree max_offset;
3839 /* If recording subobjects for a non-static data member or a
3840 non-empty base class , we do not need to record offsets beyond
3841 the size of the biggest empty class. Additional data members
3842 will go at the end of the class. Additional base classes will go
3843 either at offset zero (if empty, in which case they cannot
3844 overlap with offsets past the size of the biggest empty class) or
3845 at the end of the class.
3846
3847 However, if we are placing an empty base class, then we must record
3848 all offsets, as either the empty class is at offset zero (where
3849 other empty classes might later be placed) or at the end of the
3850 class (where other objects might then be placed, so other empty
3851 subobjects might later overlap). */
3852 if (is_data_member
3853 || !is_empty_class (BINFO_TYPE (type)))
3854 max_offset = sizeof_biggest_empty_class;
3855 else
3856 max_offset = NULL_TREE;
3857 walk_subobject_offsets (type, record_subobject_offset, offset,
3858 offsets, max_offset, is_data_member);
3859 }
3860
3861 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3862 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3863 virtual bases of TYPE are examined. */
3864
3865 static int
layout_conflict_p(tree type,tree offset,splay_tree offsets,int vbases_p)3866 layout_conflict_p (tree type,
3867 tree offset,
3868 splay_tree offsets,
3869 int vbases_p)
3870 {
3871 splay_tree_node max_node;
3872
3873 /* Get the node in OFFSETS that indicates the maximum offset where
3874 an empty subobject is located. */
3875 max_node = splay_tree_max (offsets);
3876 /* If there aren't any empty subobjects, then there's no point in
3877 performing this check. */
3878 if (!max_node)
3879 return 0;
3880
3881 return walk_subobject_offsets (type, check_subobject_offset, offset,
3882 offsets, (tree) (max_node->key),
3883 vbases_p);
3884 }
3885
3886 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3887 non-static data member of the type indicated by RLI. BINFO is the
3888 binfo corresponding to the base subobject, OFFSETS maps offsets to
3889 types already located at those offsets. This function determines
3890 the position of the DECL. */
3891
3892 static void
layout_nonempty_base_or_field(record_layout_info rli,tree decl,tree binfo,splay_tree offsets)3893 layout_nonempty_base_or_field (record_layout_info rli,
3894 tree decl,
3895 tree binfo,
3896 splay_tree offsets)
3897 {
3898 tree offset = NULL_TREE;
3899 bool field_p;
3900 tree type;
3901
3902 if (binfo)
3903 {
3904 /* For the purposes of determining layout conflicts, we want to
3905 use the class type of BINFO; TREE_TYPE (DECL) will be the
3906 CLASSTYPE_AS_BASE version, which does not contain entries for
3907 zero-sized bases. */
3908 type = TREE_TYPE (binfo);
3909 field_p = false;
3910 }
3911 else
3912 {
3913 type = TREE_TYPE (decl);
3914 field_p = true;
3915 }
3916
3917 /* Try to place the field. It may take more than one try if we have
3918 a hard time placing the field without putting two objects of the
3919 same type at the same address. */
3920 while (1)
3921 {
3922 struct record_layout_info_s old_rli = *rli;
3923
3924 /* Place this field. */
3925 place_field (rli, decl);
3926 offset = byte_position (decl);
3927
3928 /* We have to check to see whether or not there is already
3929 something of the same type at the offset we're about to use.
3930 For example, consider:
3931
3932 struct S {};
3933 struct T : public S { int i; };
3934 struct U : public S, public T {};
3935
3936 Here, we put S at offset zero in U. Then, we can't put T at
3937 offset zero -- its S component would be at the same address
3938 as the S we already allocated. So, we have to skip ahead.
3939 Since all data members, including those whose type is an
3940 empty class, have nonzero size, any overlap can happen only
3941 with a direct or indirect base-class -- it can't happen with
3942 a data member. */
3943 /* In a union, overlap is permitted; all members are placed at
3944 offset zero. */
3945 if (TREE_CODE (rli->t) == UNION_TYPE)
3946 break;
3947 /* G++ 3.2 did not check for overlaps when placing a non-empty
3948 virtual base. */
3949 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3950 break;
3951 if (layout_conflict_p (field_p ? type : binfo, offset,
3952 offsets, field_p))
3953 {
3954 /* Strip off the size allocated to this field. That puts us
3955 at the first place we could have put the field with
3956 proper alignment. */
3957 *rli = old_rli;
3958
3959 /* Bump up by the alignment required for the type. */
3960 rli->bitpos
3961 = size_binop (PLUS_EXPR, rli->bitpos,
3962 bitsize_int (binfo
3963 ? CLASSTYPE_ALIGN (type)
3964 : TYPE_ALIGN (type)));
3965 normalize_rli (rli);
3966 }
3967 else
3968 /* There was no conflict. We're done laying out this field. */
3969 break;
3970 }
3971
3972 /* Now that we know where it will be placed, update its
3973 BINFO_OFFSET. */
3974 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3975 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3976 this point because their BINFO_OFFSET is copied from another
3977 hierarchy. Therefore, we may not need to add the entire
3978 OFFSET. */
3979 propagate_binfo_offsets (binfo,
3980 size_diffop_loc (input_location,
3981 convert (ssizetype, offset),
3982 convert (ssizetype,
3983 BINFO_OFFSET (binfo))));
3984 }
3985
3986 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3987
3988 static int
empty_base_at_nonzero_offset_p(tree type,tree offset,splay_tree)3989 empty_base_at_nonzero_offset_p (tree type,
3990 tree offset,
3991 splay_tree /*offsets*/)
3992 {
3993 return is_empty_class (type) && !integer_zerop (offset);
3994 }
3995
3996 /* Layout the empty base BINFO. EOC indicates the byte currently just
3997 past the end of the class, and should be correctly aligned for a
3998 class of the type indicated by BINFO; OFFSETS gives the offsets of
3999 the empty bases allocated so far. T is the most derived
4000 type. Return nonzero iff we added it at the end. */
4001
4002 static bool
layout_empty_base(record_layout_info rli,tree binfo,tree eoc,splay_tree offsets)4003 layout_empty_base (record_layout_info rli, tree binfo,
4004 tree eoc, splay_tree offsets)
4005 {
4006 tree alignment;
4007 tree basetype = BINFO_TYPE (binfo);
4008 bool atend = false;
4009
4010 /* This routine should only be used for empty classes. */
4011 gcc_assert (is_empty_class (basetype));
4012 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
4013
4014 if (!integer_zerop (BINFO_OFFSET (binfo)))
4015 {
4016 if (abi_version_at_least (2))
4017 propagate_binfo_offsets
4018 (binfo, size_diffop_loc (input_location,
4019 size_zero_node, BINFO_OFFSET (binfo)));
4020 else
4021 warning (OPT_Wabi,
4022 "offset of empty base %qT may not be ABI-compliant and may"
4023 "change in a future version of GCC",
4024 BINFO_TYPE (binfo));
4025 }
4026
4027 /* This is an empty base class. We first try to put it at offset
4028 zero. */
4029 if (layout_conflict_p (binfo,
4030 BINFO_OFFSET (binfo),
4031 offsets,
4032 /*vbases_p=*/0))
4033 {
4034 /* That didn't work. Now, we move forward from the next
4035 available spot in the class. */
4036 atend = true;
4037 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
4038 while (1)
4039 {
4040 if (!layout_conflict_p (binfo,
4041 BINFO_OFFSET (binfo),
4042 offsets,
4043 /*vbases_p=*/0))
4044 /* We finally found a spot where there's no overlap. */
4045 break;
4046
4047 /* There's overlap here, too. Bump along to the next spot. */
4048 propagate_binfo_offsets (binfo, alignment);
4049 }
4050 }
4051
4052 if (CLASSTYPE_USER_ALIGN (basetype))
4053 {
4054 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype));
4055 if (warn_packed)
4056 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype));
4057 TYPE_USER_ALIGN (rli->t) = 1;
4058 }
4059
4060 return atend;
4061 }
4062
4063 /* Layout the base given by BINFO in the class indicated by RLI.
4064 *BASE_ALIGN is a running maximum of the alignments of
4065 any base class. OFFSETS gives the location of empty base
4066 subobjects. T is the most derived type. Return nonzero if the new
4067 object cannot be nearly-empty. A new FIELD_DECL is inserted at
4068 *NEXT_FIELD, unless BINFO is for an empty base class.
4069
4070 Returns the location at which the next field should be inserted. */
4071
4072 static tree *
build_base_field(record_layout_info rli,tree binfo,splay_tree offsets,tree * next_field)4073 build_base_field (record_layout_info rli, tree binfo,
4074 splay_tree offsets, tree *next_field)
4075 {
4076 tree t = rli->t;
4077 tree basetype = BINFO_TYPE (binfo);
4078
4079 if (!COMPLETE_TYPE_P (basetype))
4080 /* This error is now reported in xref_tag, thus giving better
4081 location information. */
4082 return next_field;
4083
4084 /* Place the base class. */
4085 if (!is_empty_class (basetype))
4086 {
4087 tree decl;
4088
4089 /* The containing class is non-empty because it has a non-empty
4090 base class. */
4091 CLASSTYPE_EMPTY_P (t) = 0;
4092
4093 /* Create the FIELD_DECL. */
4094 decl = build_decl (input_location,
4095 FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
4096 DECL_ARTIFICIAL (decl) = 1;
4097 DECL_IGNORED_P (decl) = 1;
4098 DECL_FIELD_CONTEXT (decl) = t;
4099 if (CLASSTYPE_AS_BASE (basetype))
4100 {
4101 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
4102 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
4103 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
4104 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
4105 DECL_MODE (decl) = TYPE_MODE (basetype);
4106 DECL_FIELD_IS_BASE (decl) = 1;
4107
4108 /* Try to place the field. It may take more than one try if we
4109 have a hard time placing the field without putting two
4110 objects of the same type at the same address. */
4111 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
4112 /* Add the new FIELD_DECL to the list of fields for T. */
4113 DECL_CHAIN (decl) = *next_field;
4114 *next_field = decl;
4115 next_field = &DECL_CHAIN (decl);
4116 }
4117 }
4118 else
4119 {
4120 tree eoc;
4121 bool atend;
4122
4123 /* On some platforms (ARM), even empty classes will not be
4124 byte-aligned. */
4125 eoc = round_up_loc (input_location,
4126 rli_size_unit_so_far (rli),
4127 CLASSTYPE_ALIGN_UNIT (basetype));
4128 atend = layout_empty_base (rli, binfo, eoc, offsets);
4129 /* A nearly-empty class "has no proper base class that is empty,
4130 not morally virtual, and at an offset other than zero." */
4131 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
4132 {
4133 if (atend)
4134 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4135 /* The check above (used in G++ 3.2) is insufficient because
4136 an empty class placed at offset zero might itself have an
4137 empty base at a nonzero offset. */
4138 else if (walk_subobject_offsets (basetype,
4139 empty_base_at_nonzero_offset_p,
4140 size_zero_node,
4141 /*offsets=*/NULL,
4142 /*max_offset=*/NULL_TREE,
4143 /*vbases_p=*/true))
4144 {
4145 if (abi_version_at_least (2))
4146 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4147 else
4148 warning (OPT_Wabi,
4149 "class %qT will be considered nearly empty in a "
4150 "future version of GCC", t);
4151 }
4152 }
4153
4154 /* We do not create a FIELD_DECL for empty base classes because
4155 it might overlap some other field. We want to be able to
4156 create CONSTRUCTORs for the class by iterating over the
4157 FIELD_DECLs, and the back end does not handle overlapping
4158 FIELD_DECLs. */
4159
4160 /* An empty virtual base causes a class to be non-empty
4161 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
4162 here because that was already done when the virtual table
4163 pointer was created. */
4164 }
4165
4166 /* Record the offsets of BINFO and its base subobjects. */
4167 record_subobject_offsets (binfo,
4168 BINFO_OFFSET (binfo),
4169 offsets,
4170 /*is_data_member=*/false);
4171
4172 return next_field;
4173 }
4174
4175 /* Layout all of the non-virtual base classes. Record empty
4176 subobjects in OFFSETS. T is the most derived type. Return nonzero
4177 if the type cannot be nearly empty. The fields created
4178 corresponding to the base classes will be inserted at
4179 *NEXT_FIELD. */
4180
4181 static void
build_base_fields(record_layout_info rli,splay_tree offsets,tree * next_field)4182 build_base_fields (record_layout_info rli,
4183 splay_tree offsets, tree *next_field)
4184 {
4185 /* Chain to hold all the new FIELD_DECLs which stand in for base class
4186 subobjects. */
4187 tree t = rli->t;
4188 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
4189 int i;
4190
4191 /* The primary base class is always allocated first. */
4192 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
4193 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
4194 offsets, next_field);
4195
4196 /* Now allocate the rest of the bases. */
4197 for (i = 0; i < n_baseclasses; ++i)
4198 {
4199 tree base_binfo;
4200
4201 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
4202
4203 /* The primary base was already allocated above, so we don't
4204 need to allocate it again here. */
4205 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
4206 continue;
4207
4208 /* Virtual bases are added at the end (a primary virtual base
4209 will have already been added). */
4210 if (BINFO_VIRTUAL_P (base_binfo))
4211 continue;
4212
4213 next_field = build_base_field (rli, base_binfo,
4214 offsets, next_field);
4215 }
4216 }
4217
4218 /* Go through the TYPE_METHODS of T issuing any appropriate
4219 diagnostics, figuring out which methods override which other
4220 methods, and so forth. */
4221
4222 static void
check_methods(tree t)4223 check_methods (tree t)
4224 {
4225 tree x;
4226
4227 for (x = TYPE_METHODS (t); x; x = DECL_CHAIN (x))
4228 {
4229 check_for_override (x, t);
4230 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
4231 error ("initializer specified for non-virtual method %q+D", x);
4232 /* The name of the field is the original field name
4233 Save this in auxiliary field for later overloading. */
4234 if (DECL_VINDEX (x))
4235 {
4236 TYPE_POLYMORPHIC_P (t) = 1;
4237 if (DECL_PURE_VIRTUAL_P (x))
4238 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x);
4239 }
4240 /* All user-provided destructors are non-trivial.
4241 Constructors and assignment ops are handled in
4242 grok_special_member_properties. */
4243 if (DECL_DESTRUCTOR_P (x) && user_provided_p (x))
4244 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
4245 }
4246 }
4247
4248 /* FN is a constructor or destructor. Clone the declaration to create
4249 a specialized in-charge or not-in-charge version, as indicated by
4250 NAME. */
4251
4252 static tree
build_clone(tree fn,tree name)4253 build_clone (tree fn, tree name)
4254 {
4255 tree parms;
4256 tree clone;
4257
4258 /* Copy the function. */
4259 clone = copy_decl (fn);
4260 /* Reset the function name. */
4261 DECL_NAME (clone) = name;
4262 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
4263 /* Remember where this function came from. */
4264 DECL_ABSTRACT_ORIGIN (clone) = fn;
4265 /* Make it easy to find the CLONE given the FN. */
4266 DECL_CHAIN (clone) = DECL_CHAIN (fn);
4267 DECL_CHAIN (fn) = clone;
4268
4269 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
4270 if (TREE_CODE (clone) == TEMPLATE_DECL)
4271 {
4272 tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name);
4273 DECL_TEMPLATE_RESULT (clone) = result;
4274 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
4275 DECL_TI_TEMPLATE (result) = clone;
4276 TREE_TYPE (clone) = TREE_TYPE (result);
4277 return clone;
4278 }
4279
4280 DECL_CLONED_FUNCTION (clone) = fn;
4281 /* There's no pending inline data for this function. */
4282 DECL_PENDING_INLINE_INFO (clone) = NULL;
4283 DECL_PENDING_INLINE_P (clone) = 0;
4284
4285 /* The base-class destructor is not virtual. */
4286 if (name == base_dtor_identifier)
4287 {
4288 DECL_VIRTUAL_P (clone) = 0;
4289 if (TREE_CODE (clone) != TEMPLATE_DECL)
4290 DECL_VINDEX (clone) = NULL_TREE;
4291 }
4292
4293 /* If there was an in-charge parameter, drop it from the function
4294 type. */
4295 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
4296 {
4297 tree basetype;
4298 tree parmtypes;
4299 tree exceptions;
4300
4301 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4302 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4303 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
4304 /* Skip the `this' parameter. */
4305 parmtypes = TREE_CHAIN (parmtypes);
4306 /* Skip the in-charge parameter. */
4307 parmtypes = TREE_CHAIN (parmtypes);
4308 /* And the VTT parm, in a complete [cd]tor. */
4309 if (DECL_HAS_VTT_PARM_P (fn)
4310 && ! DECL_NEEDS_VTT_PARM_P (clone))
4311 parmtypes = TREE_CHAIN (parmtypes);
4312 /* If this is subobject constructor or destructor, add the vtt
4313 parameter. */
4314 TREE_TYPE (clone)
4315 = build_method_type_directly (basetype,
4316 TREE_TYPE (TREE_TYPE (clone)),
4317 parmtypes);
4318 if (exceptions)
4319 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
4320 exceptions);
4321 TREE_TYPE (clone)
4322 = cp_build_type_attribute_variant (TREE_TYPE (clone),
4323 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
4324 }
4325
4326 /* Copy the function parameters. */
4327 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
4328 /* Remove the in-charge parameter. */
4329 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
4330 {
4331 DECL_CHAIN (DECL_ARGUMENTS (clone))
4332 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone)));
4333 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
4334 }
4335 /* And the VTT parm, in a complete [cd]tor. */
4336 if (DECL_HAS_VTT_PARM_P (fn))
4337 {
4338 if (DECL_NEEDS_VTT_PARM_P (clone))
4339 DECL_HAS_VTT_PARM_P (clone) = 1;
4340 else
4341 {
4342 DECL_CHAIN (DECL_ARGUMENTS (clone))
4343 = DECL_CHAIN (DECL_CHAIN (DECL_ARGUMENTS (clone)));
4344 DECL_HAS_VTT_PARM_P (clone) = 0;
4345 }
4346 }
4347
4348 for (parms = DECL_ARGUMENTS (clone); parms; parms = DECL_CHAIN (parms))
4349 {
4350 DECL_CONTEXT (parms) = clone;
4351 cxx_dup_lang_specific_decl (parms);
4352 }
4353
4354 /* Create the RTL for this function. */
4355 SET_DECL_RTL (clone, NULL);
4356 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
4357
4358 if (pch_file)
4359 note_decl_for_pch (clone);
4360
4361 return clone;
4362 }
4363
4364 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
4365 not invoke this function directly.
4366
4367 For a non-thunk function, returns the address of the slot for storing
4368 the function it is a clone of. Otherwise returns NULL_TREE.
4369
4370 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
4371 cloned_function is unset. This is to support the separate
4372 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
4373 on a template makes sense, but not the former. */
4374
4375 tree *
decl_cloned_function_p(const_tree decl,bool just_testing)4376 decl_cloned_function_p (const_tree decl, bool just_testing)
4377 {
4378 tree *ptr;
4379 if (just_testing)
4380 decl = STRIP_TEMPLATE (decl);
4381
4382 if (TREE_CODE (decl) != FUNCTION_DECL
4383 || !DECL_LANG_SPECIFIC (decl)
4384 || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p)
4385 {
4386 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
4387 if (!just_testing)
4388 lang_check_failed (__FILE__, __LINE__, __FUNCTION__);
4389 else
4390 #endif
4391 return NULL;
4392 }
4393
4394 ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function;
4395 if (just_testing && *ptr == NULL_TREE)
4396 return NULL;
4397 else
4398 return ptr;
4399 }
4400
4401 /* Produce declarations for all appropriate clones of FN. If
4402 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4403 CLASTYPE_METHOD_VEC as well. */
4404
4405 void
clone_function_decl(tree fn,int update_method_vec_p)4406 clone_function_decl (tree fn, int update_method_vec_p)
4407 {
4408 tree clone;
4409
4410 /* Avoid inappropriate cloning. */
4411 if (DECL_CHAIN (fn)
4412 && DECL_CLONED_FUNCTION_P (DECL_CHAIN (fn)))
4413 return;
4414
4415 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
4416 {
4417 /* For each constructor, we need two variants: an in-charge version
4418 and a not-in-charge version. */
4419 clone = build_clone (fn, complete_ctor_identifier);
4420 if (update_method_vec_p)
4421 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4422 clone = build_clone (fn, base_ctor_identifier);
4423 if (update_method_vec_p)
4424 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4425 }
4426 else
4427 {
4428 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
4429
4430 /* For each destructor, we need three variants: an in-charge
4431 version, a not-in-charge version, and an in-charge deleting
4432 version. We clone the deleting version first because that
4433 means it will go second on the TYPE_METHODS list -- and that
4434 corresponds to the correct layout order in the virtual
4435 function table.
4436
4437 For a non-virtual destructor, we do not build a deleting
4438 destructor. */
4439 if (DECL_VIRTUAL_P (fn))
4440 {
4441 clone = build_clone (fn, deleting_dtor_identifier);
4442 if (update_method_vec_p)
4443 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4444 }
4445 clone = build_clone (fn, complete_dtor_identifier);
4446 if (update_method_vec_p)
4447 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4448 clone = build_clone (fn, base_dtor_identifier);
4449 if (update_method_vec_p)
4450 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4451 }
4452
4453 /* Note that this is an abstract function that is never emitted. */
4454 DECL_ABSTRACT (fn) = 1;
4455 }
4456
4457 /* DECL is an in charge constructor, which is being defined. This will
4458 have had an in class declaration, from whence clones were
4459 declared. An out-of-class definition can specify additional default
4460 arguments. As it is the clones that are involved in overload
4461 resolution, we must propagate the information from the DECL to its
4462 clones. */
4463
4464 void
adjust_clone_args(tree decl)4465 adjust_clone_args (tree decl)
4466 {
4467 tree clone;
4468
4469 for (clone = DECL_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone);
4470 clone = DECL_CHAIN (clone))
4471 {
4472 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
4473 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
4474 tree decl_parms, clone_parms;
4475
4476 clone_parms = orig_clone_parms;
4477
4478 /* Skip the 'this' parameter. */
4479 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
4480 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4481
4482 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
4483 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4484 if (DECL_HAS_VTT_PARM_P (decl))
4485 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4486
4487 clone_parms = orig_clone_parms;
4488 if (DECL_HAS_VTT_PARM_P (clone))
4489 clone_parms = TREE_CHAIN (clone_parms);
4490
4491 for (decl_parms = orig_decl_parms; decl_parms;
4492 decl_parms = TREE_CHAIN (decl_parms),
4493 clone_parms = TREE_CHAIN (clone_parms))
4494 {
4495 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
4496 TREE_TYPE (clone_parms)));
4497
4498 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
4499 {
4500 /* A default parameter has been added. Adjust the
4501 clone's parameters. */
4502 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4503 tree attrs = TYPE_ATTRIBUTES (TREE_TYPE (clone));
4504 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4505 tree type;
4506
4507 clone_parms = orig_decl_parms;
4508
4509 if (DECL_HAS_VTT_PARM_P (clone))
4510 {
4511 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
4512 TREE_VALUE (orig_clone_parms),
4513 clone_parms);
4514 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
4515 }
4516 type = build_method_type_directly (basetype,
4517 TREE_TYPE (TREE_TYPE (clone)),
4518 clone_parms);
4519 if (exceptions)
4520 type = build_exception_variant (type, exceptions);
4521 if (attrs)
4522 type = cp_build_type_attribute_variant (type, attrs);
4523 TREE_TYPE (clone) = type;
4524
4525 clone_parms = NULL_TREE;
4526 break;
4527 }
4528 }
4529 gcc_assert (!clone_parms);
4530 }
4531 }
4532
4533 /* For each of the constructors and destructors in T, create an
4534 in-charge and not-in-charge variant. */
4535
4536 static void
clone_constructors_and_destructors(tree t)4537 clone_constructors_and_destructors (tree t)
4538 {
4539 tree fns;
4540
4541 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4542 out now. */
4543 if (!CLASSTYPE_METHOD_VEC (t))
4544 return;
4545
4546 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4547 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4548 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4549 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4550 }
4551
4552 /* Deduce noexcept for a destructor DTOR. */
4553
4554 void
deduce_noexcept_on_destructor(tree dtor)4555 deduce_noexcept_on_destructor (tree dtor)
4556 {
4557 if (!TYPE_RAISES_EXCEPTIONS (TREE_TYPE (dtor)))
4558 {
4559 tree ctx = DECL_CONTEXT (dtor);
4560 tree implicit_fn = implicitly_declare_fn (sfk_destructor, ctx,
4561 /*const_p=*/false,
4562 NULL, NULL);
4563 tree eh_spec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (implicit_fn));
4564 TREE_TYPE (dtor) = build_exception_variant (TREE_TYPE (dtor), eh_spec);
4565 }
4566 }
4567
4568 /* For each destructor in T, deduce noexcept:
4569
4570 12.4/3: A declaration of a destructor that does not have an
4571 exception-specification is implicitly considered to have the
4572 same exception-specification as an implicit declaration (15.4). */
4573
4574 static void
deduce_noexcept_on_destructors(tree t)4575 deduce_noexcept_on_destructors (tree t)
4576 {
4577 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4578 out now. */
4579 if (!CLASSTYPE_METHOD_VEC (t))
4580 return;
4581
4582 bool saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
4583
4584 /* Avoid early exit from synthesized_method_walk (c++/57645). */
4585 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = true;
4586
4587 for (tree fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4588 deduce_noexcept_on_destructor (OVL_CURRENT (fns));
4589
4590 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = saved_nontrivial_dtor;
4591 }
4592
4593 /* Subroutine of set_one_vmethod_tm_attributes. Search base classes
4594 of TYPE for virtual functions which FNDECL overrides. Return a
4595 mask of the tm attributes found therein. */
4596
4597 static int
look_for_tm_attr_overrides(tree type,tree fndecl)4598 look_for_tm_attr_overrides (tree type, tree fndecl)
4599 {
4600 tree binfo = TYPE_BINFO (type);
4601 tree base_binfo;
4602 int ix, found = 0;
4603
4604 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ++ix)
4605 {
4606 tree o, basetype = BINFO_TYPE (base_binfo);
4607
4608 if (!TYPE_POLYMORPHIC_P (basetype))
4609 continue;
4610
4611 o = look_for_overrides_here (basetype, fndecl);
4612 if (o)
4613 found |= tm_attr_to_mask (find_tm_attribute
4614 (TYPE_ATTRIBUTES (TREE_TYPE (o))));
4615 else
4616 found |= look_for_tm_attr_overrides (basetype, fndecl);
4617 }
4618
4619 return found;
4620 }
4621
4622 /* Subroutine of set_method_tm_attributes. Handle the checks and
4623 inheritance for one virtual method FNDECL. */
4624
4625 static void
set_one_vmethod_tm_attributes(tree type,tree fndecl)4626 set_one_vmethod_tm_attributes (tree type, tree fndecl)
4627 {
4628 tree tm_attr;
4629 int found, have;
4630
4631 found = look_for_tm_attr_overrides (type, fndecl);
4632
4633 /* If FNDECL doesn't actually override anything (i.e. T is the
4634 class that first declares FNDECL virtual), then we're done. */
4635 if (found == 0)
4636 return;
4637
4638 tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl)));
4639 have = tm_attr_to_mask (tm_attr);
4640
4641 /* Intel STM Language Extension 3.0, Section 4.2 table 4:
4642 tm_pure must match exactly, otherwise no weakening of
4643 tm_safe > tm_callable > nothing. */
4644 /* ??? The tm_pure attribute didn't make the transition to the
4645 multivendor language spec. */
4646 if (have == TM_ATTR_PURE)
4647 {
4648 if (found != TM_ATTR_PURE)
4649 {
4650 found &= -found;
4651 goto err_override;
4652 }
4653 }
4654 /* If the overridden function is tm_pure, then FNDECL must be. */
4655 else if (found == TM_ATTR_PURE && tm_attr)
4656 goto err_override;
4657 /* Look for base class combinations that cannot be satisfied. */
4658 else if (found != TM_ATTR_PURE && (found & TM_ATTR_PURE))
4659 {
4660 found &= ~TM_ATTR_PURE;
4661 found &= -found;
4662 error_at (DECL_SOURCE_LOCATION (fndecl),
4663 "method overrides both %<transaction_pure%> and %qE methods",
4664 tm_mask_to_attr (found));
4665 }
4666 /* If FNDECL did not declare an attribute, then inherit the most
4667 restrictive one. */
4668 else if (tm_attr == NULL)
4669 {
4670 apply_tm_attr (fndecl, tm_mask_to_attr (found & -found));
4671 }
4672 /* Otherwise validate that we're not weaker than a function
4673 that is being overridden. */
4674 else
4675 {
4676 found &= -found;
4677 if (found <= TM_ATTR_CALLABLE && have > found)
4678 goto err_override;
4679 }
4680 return;
4681
4682 err_override:
4683 error_at (DECL_SOURCE_LOCATION (fndecl),
4684 "method declared %qE overriding %qE method",
4685 tm_attr, tm_mask_to_attr (found));
4686 }
4687
4688 /* For each of the methods in T, propagate a class-level tm attribute. */
4689
4690 static void
set_method_tm_attributes(tree t)4691 set_method_tm_attributes (tree t)
4692 {
4693 tree class_tm_attr, fndecl;
4694
4695 /* Don't bother collecting tm attributes if transactional memory
4696 support is not enabled. */
4697 if (!flag_tm)
4698 return;
4699
4700 /* Process virtual methods first, as they inherit directly from the
4701 base virtual function and also require validation of new attributes. */
4702 if (TYPE_CONTAINS_VPTR_P (t))
4703 {
4704 tree vchain;
4705 for (vchain = BINFO_VIRTUALS (TYPE_BINFO (t)); vchain;
4706 vchain = TREE_CHAIN (vchain))
4707 {
4708 fndecl = BV_FN (vchain);
4709 if (DECL_THUNK_P (fndecl))
4710 fndecl = THUNK_TARGET (fndecl);
4711 set_one_vmethod_tm_attributes (t, fndecl);
4712 }
4713 }
4714
4715 /* If the class doesn't have an attribute, nothing more to do. */
4716 class_tm_attr = find_tm_attribute (TYPE_ATTRIBUTES (t));
4717 if (class_tm_attr == NULL)
4718 return;
4719
4720 /* Any method that does not yet have a tm attribute inherits
4721 the one from the class. */
4722 for (fndecl = TYPE_METHODS (t); fndecl; fndecl = TREE_CHAIN (fndecl))
4723 {
4724 if (!find_tm_attribute (TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
4725 apply_tm_attr (fndecl, class_tm_attr);
4726 }
4727 }
4728
4729 /* Returns true iff class T has a user-defined constructor other than
4730 the default constructor. */
4731
4732 bool
type_has_user_nondefault_constructor(tree t)4733 type_has_user_nondefault_constructor (tree t)
4734 {
4735 tree fns;
4736
4737 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4738 return false;
4739
4740 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4741 {
4742 tree fn = OVL_CURRENT (fns);
4743 if (!DECL_ARTIFICIAL (fn)
4744 && (TREE_CODE (fn) == TEMPLATE_DECL
4745 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
4746 != NULL_TREE)))
4747 return true;
4748 }
4749
4750 return false;
4751 }
4752
4753 /* Returns the defaulted constructor if T has one. Otherwise, returns
4754 NULL_TREE. */
4755
4756 tree
in_class_defaulted_default_constructor(tree t)4757 in_class_defaulted_default_constructor (tree t)
4758 {
4759 tree fns, args;
4760
4761 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4762 return NULL_TREE;
4763
4764 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4765 {
4766 tree fn = OVL_CURRENT (fns);
4767
4768 if (DECL_DEFAULTED_IN_CLASS_P (fn))
4769 {
4770 args = FUNCTION_FIRST_USER_PARMTYPE (fn);
4771 while (args && TREE_PURPOSE (args))
4772 args = TREE_CHAIN (args);
4773 if (!args || args == void_list_node)
4774 return fn;
4775 }
4776 }
4777
4778 return NULL_TREE;
4779 }
4780
4781 /* Returns true iff FN is a user-provided function, i.e. user-declared
4782 and not defaulted at its first declaration; or explicit, private,
4783 protected, or non-const. */
4784
4785 bool
user_provided_p(tree fn)4786 user_provided_p (tree fn)
4787 {
4788 if (TREE_CODE (fn) == TEMPLATE_DECL)
4789 return true;
4790 else
4791 return (!DECL_ARTIFICIAL (fn)
4792 && !DECL_DEFAULTED_IN_CLASS_P (fn));
4793 }
4794
4795 /* Returns true iff class T has a user-provided constructor. */
4796
4797 bool
type_has_user_provided_constructor(tree t)4798 type_has_user_provided_constructor (tree t)
4799 {
4800 tree fns;
4801
4802 if (!CLASS_TYPE_P (t))
4803 return false;
4804
4805 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4806 return false;
4807
4808 /* This can happen in error cases; avoid crashing. */
4809 if (!CLASSTYPE_METHOD_VEC (t))
4810 return false;
4811
4812 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4813 if (user_provided_p (OVL_CURRENT (fns)))
4814 return true;
4815
4816 return false;
4817 }
4818
4819 /* Returns true iff class T has a user-provided default constructor. */
4820
4821 bool
type_has_user_provided_default_constructor(tree t)4822 type_has_user_provided_default_constructor (tree t)
4823 {
4824 tree fns;
4825
4826 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4827 return false;
4828
4829 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4830 {
4831 tree fn = OVL_CURRENT (fns);
4832 if (TREE_CODE (fn) == FUNCTION_DECL
4833 && user_provided_p (fn)
4834 && sufficient_parms_p (FUNCTION_FIRST_USER_PARMTYPE (fn)))
4835 return true;
4836 }
4837
4838 return false;
4839 }
4840
4841 /* TYPE is being used as a virtual base, and has a non-trivial move
4842 assignment. Return true if this is due to there being a user-provided
4843 move assignment in TYPE or one of its subobjects; if there isn't, then
4844 multiple move assignment can't cause any harm. */
4845
4846 bool
vbase_has_user_provided_move_assign(tree type)4847 vbase_has_user_provided_move_assign (tree type)
4848 {
4849 /* Does the type itself have a user-provided move assignment operator? */
4850 for (tree fns
4851 = lookup_fnfields_slot_nolazy (type, ansi_assopname (NOP_EXPR));
4852 fns; fns = OVL_NEXT (fns))
4853 {
4854 tree fn = OVL_CURRENT (fns);
4855 if (move_fn_p (fn) && user_provided_p (fn))
4856 return true;
4857 }
4858
4859 /* Do any of its bases? */
4860 tree binfo = TYPE_BINFO (type);
4861 tree base_binfo;
4862 for (int i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4863 if (vbase_has_user_provided_move_assign (BINFO_TYPE (base_binfo)))
4864 return true;
4865
4866 /* Or non-static data members? */
4867 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
4868 {
4869 if (TREE_CODE (field) == FIELD_DECL
4870 && CLASS_TYPE_P (TREE_TYPE (field))
4871 && vbase_has_user_provided_move_assign (TREE_TYPE (field)))
4872 return true;
4873 }
4874
4875 /* Seems not. */
4876 return false;
4877 }
4878
4879 /* If default-initialization leaves part of TYPE uninitialized, returns
4880 a DECL for the field or TYPE itself (DR 253). */
4881
4882 tree
default_init_uninitialized_part(tree type)4883 default_init_uninitialized_part (tree type)
4884 {
4885 tree t, r, binfo;
4886 int i;
4887
4888 type = strip_array_types (type);
4889 if (!CLASS_TYPE_P (type))
4890 return type;
4891 if (type_has_user_provided_default_constructor (type))
4892 return NULL_TREE;
4893 for (binfo = TYPE_BINFO (type), i = 0;
4894 BINFO_BASE_ITERATE (binfo, i, t); ++i)
4895 {
4896 r = default_init_uninitialized_part (BINFO_TYPE (t));
4897 if (r)
4898 return r;
4899 }
4900 for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t))
4901 if (TREE_CODE (t) == FIELD_DECL
4902 && !DECL_ARTIFICIAL (t)
4903 && !DECL_INITIAL (t))
4904 {
4905 r = default_init_uninitialized_part (TREE_TYPE (t));
4906 if (r)
4907 return DECL_P (r) ? r : t;
4908 }
4909
4910 return NULL_TREE;
4911 }
4912
4913 /* Returns true iff for class T, a trivial synthesized default constructor
4914 would be constexpr. */
4915
4916 bool
trivial_default_constructor_is_constexpr(tree t)4917 trivial_default_constructor_is_constexpr (tree t)
4918 {
4919 /* A defaulted trivial default constructor is constexpr
4920 if there is nothing to initialize. */
4921 gcc_assert (!TYPE_HAS_COMPLEX_DFLT (t));
4922 return is_really_empty_class (t);
4923 }
4924
4925 /* Returns true iff class T has a constexpr default constructor. */
4926
4927 bool
type_has_constexpr_default_constructor(tree t)4928 type_has_constexpr_default_constructor (tree t)
4929 {
4930 tree fns;
4931
4932 if (!CLASS_TYPE_P (t))
4933 {
4934 /* The caller should have stripped an enclosing array. */
4935 gcc_assert (TREE_CODE (t) != ARRAY_TYPE);
4936 return false;
4937 }
4938 if (CLASSTYPE_LAZY_DEFAULT_CTOR (t))
4939 {
4940 if (!TYPE_HAS_COMPLEX_DFLT (t))
4941 return trivial_default_constructor_is_constexpr (t);
4942 /* Non-trivial, we need to check subobject constructors. */
4943 lazily_declare_fn (sfk_constructor, t);
4944 }
4945 fns = locate_ctor (t);
4946 return (fns && DECL_DECLARED_CONSTEXPR_P (fns));
4947 }
4948
4949 /* Returns true iff class TYPE has a virtual destructor. */
4950
4951 bool
type_has_virtual_destructor(tree type)4952 type_has_virtual_destructor (tree type)
4953 {
4954 tree dtor;
4955
4956 if (!CLASS_TYPE_P (type))
4957 return false;
4958
4959 gcc_assert (COMPLETE_TYPE_P (type));
4960 dtor = CLASSTYPE_DESTRUCTORS (type);
4961 return (dtor && DECL_VIRTUAL_P (dtor));
4962 }
4963
4964 /* Returns true iff class T has a move constructor. */
4965
4966 bool
type_has_move_constructor(tree t)4967 type_has_move_constructor (tree t)
4968 {
4969 tree fns;
4970
4971 if (CLASSTYPE_LAZY_MOVE_CTOR (t))
4972 {
4973 gcc_assert (COMPLETE_TYPE_P (t));
4974 lazily_declare_fn (sfk_move_constructor, t);
4975 }
4976
4977 if (!CLASSTYPE_METHOD_VEC (t))
4978 return false;
4979
4980 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4981 if (move_fn_p (OVL_CURRENT (fns)))
4982 return true;
4983
4984 return false;
4985 }
4986
4987 /* Returns true iff class T has a move assignment operator. */
4988
4989 bool
type_has_move_assign(tree t)4990 type_has_move_assign (tree t)
4991 {
4992 tree fns;
4993
4994 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t))
4995 {
4996 gcc_assert (COMPLETE_TYPE_P (t));
4997 lazily_declare_fn (sfk_move_assignment, t);
4998 }
4999
5000 for (fns = lookup_fnfields_slot_nolazy (t, ansi_assopname (NOP_EXPR));
5001 fns; fns = OVL_NEXT (fns))
5002 if (move_fn_p (OVL_CURRENT (fns)))
5003 return true;
5004
5005 return false;
5006 }
5007
5008 /* Returns true iff class T has a move constructor that was explicitly
5009 declared in the class body. Note that this is different from
5010 "user-provided", which doesn't include functions that are defaulted in
5011 the class. */
5012
5013 bool
type_has_user_declared_move_constructor(tree t)5014 type_has_user_declared_move_constructor (tree t)
5015 {
5016 tree fns;
5017
5018 if (CLASSTYPE_LAZY_MOVE_CTOR (t))
5019 return false;
5020
5021 if (!CLASSTYPE_METHOD_VEC (t))
5022 return false;
5023
5024 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
5025 {
5026 tree fn = OVL_CURRENT (fns);
5027 if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn))
5028 return true;
5029 }
5030
5031 return false;
5032 }
5033
5034 /* Returns true iff class T has a move assignment operator that was
5035 explicitly declared in the class body. */
5036
5037 bool
type_has_user_declared_move_assign(tree t)5038 type_has_user_declared_move_assign (tree t)
5039 {
5040 tree fns;
5041
5042 if (CLASSTYPE_LAZY_MOVE_ASSIGN (t))
5043 return false;
5044
5045 for (fns = lookup_fnfields_slot_nolazy (t, ansi_assopname (NOP_EXPR));
5046 fns; fns = OVL_NEXT (fns))
5047 {
5048 tree fn = OVL_CURRENT (fns);
5049 if (move_fn_p (fn) && !DECL_ARTIFICIAL (fn))
5050 return true;
5051 }
5052
5053 return false;
5054 }
5055
5056 /* Nonzero if we need to build up a constructor call when initializing an
5057 object of this class, either because it has a user-provided constructor
5058 or because it doesn't have a default constructor (so we need to give an
5059 error if no initializer is provided). Use TYPE_NEEDS_CONSTRUCTING when
5060 what you care about is whether or not an object can be produced by a
5061 constructor (e.g. so we don't set TREE_READONLY on const variables of
5062 such type); use this function when what you care about is whether or not
5063 to try to call a constructor to create an object. The latter case is
5064 the former plus some cases of constructors that cannot be called. */
5065
5066 bool
type_build_ctor_call(tree t)5067 type_build_ctor_call (tree t)
5068 {
5069 tree inner;
5070 if (TYPE_NEEDS_CONSTRUCTING (t))
5071 return true;
5072 inner = strip_array_types (t);
5073 return (CLASS_TYPE_P (inner) && !TYPE_HAS_DEFAULT_CONSTRUCTOR (inner)
5074 && !ANON_AGGR_TYPE_P (inner));
5075 }
5076
5077 /* Remove all zero-width bit-fields from T. */
5078
5079 static void
remove_zero_width_bit_fields(tree t)5080 remove_zero_width_bit_fields (tree t)
5081 {
5082 tree *fieldsp;
5083
5084 fieldsp = &TYPE_FIELDS (t);
5085 while (*fieldsp)
5086 {
5087 if (TREE_CODE (*fieldsp) == FIELD_DECL
5088 && DECL_C_BIT_FIELD (*fieldsp)
5089 /* We should not be confused by the fact that grokbitfield
5090 temporarily sets the width of the bit field into
5091 DECL_INITIAL (*fieldsp).
5092 check_bitfield_decl eventually sets DECL_SIZE (*fieldsp)
5093 to that width. */
5094 && integer_zerop (DECL_SIZE (*fieldsp)))
5095 *fieldsp = DECL_CHAIN (*fieldsp);
5096 else
5097 fieldsp = &DECL_CHAIN (*fieldsp);
5098 }
5099 }
5100
5101 /* Returns TRUE iff we need a cookie when dynamically allocating an
5102 array whose elements have the indicated class TYPE. */
5103
5104 static bool
type_requires_array_cookie(tree type)5105 type_requires_array_cookie (tree type)
5106 {
5107 tree fns;
5108 bool has_two_argument_delete_p = false;
5109
5110 gcc_assert (CLASS_TYPE_P (type));
5111
5112 /* If there's a non-trivial destructor, we need a cookie. In order
5113 to iterate through the array calling the destructor for each
5114 element, we'll have to know how many elements there are. */
5115 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
5116 return true;
5117
5118 /* If the usual deallocation function is a two-argument whose second
5119 argument is of type `size_t', then we have to pass the size of
5120 the array to the deallocation function, so we will need to store
5121 a cookie. */
5122 fns = lookup_fnfields (TYPE_BINFO (type),
5123 ansi_opname (VEC_DELETE_EXPR),
5124 /*protect=*/0);
5125 /* If there are no `operator []' members, or the lookup is
5126 ambiguous, then we don't need a cookie. */
5127 if (!fns || fns == error_mark_node)
5128 return false;
5129 /* Loop through all of the functions. */
5130 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
5131 {
5132 tree fn;
5133 tree second_parm;
5134
5135 /* Select the current function. */
5136 fn = OVL_CURRENT (fns);
5137 /* See if this function is a one-argument delete function. If
5138 it is, then it will be the usual deallocation function. */
5139 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
5140 if (second_parm == void_list_node)
5141 return false;
5142 /* Do not consider this function if its second argument is an
5143 ellipsis. */
5144 if (!second_parm)
5145 continue;
5146 /* Otherwise, if we have a two-argument function and the second
5147 argument is `size_t', it will be the usual deallocation
5148 function -- unless there is one-argument function, too. */
5149 if (TREE_CHAIN (second_parm) == void_list_node
5150 && same_type_p (TREE_VALUE (second_parm), size_type_node))
5151 has_two_argument_delete_p = true;
5152 }
5153
5154 return has_two_argument_delete_p;
5155 }
5156
5157 /* Finish computing the `literal type' property of class type T.
5158
5159 At this point, we have already processed base classes and
5160 non-static data members. We need to check whether the copy
5161 constructor is trivial, the destructor is trivial, and there
5162 is a trivial default constructor or at least one constexpr
5163 constructor other than the copy constructor. */
5164
5165 static void
finalize_literal_type_property(tree t)5166 finalize_literal_type_property (tree t)
5167 {
5168 tree fn;
5169
5170 if (cxx_dialect < cxx0x
5171 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
5172 CLASSTYPE_LITERAL_P (t) = false;
5173 else if (CLASSTYPE_LITERAL_P (t) && !TYPE_HAS_TRIVIAL_DFLT (t)
5174 && CLASSTYPE_NON_AGGREGATE (t)
5175 && !TYPE_HAS_CONSTEXPR_CTOR (t))
5176 CLASSTYPE_LITERAL_P (t) = false;
5177
5178 if (!CLASSTYPE_LITERAL_P (t))
5179 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn))
5180 if (DECL_DECLARED_CONSTEXPR_P (fn)
5181 && TREE_CODE (fn) != TEMPLATE_DECL
5182 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
5183 && !DECL_CONSTRUCTOR_P (fn))
5184 {
5185 DECL_DECLARED_CONSTEXPR_P (fn) = false;
5186 if (!DECL_GENERATED_P (fn))
5187 {
5188 error ("enclosing class of constexpr non-static member "
5189 "function %q+#D is not a literal type", fn);
5190 explain_non_literal_class (t);
5191 }
5192 }
5193 }
5194
5195 /* T is a non-literal type used in a context which requires a constant
5196 expression. Explain why it isn't literal. */
5197
5198 void
explain_non_literal_class(tree t)5199 explain_non_literal_class (tree t)
5200 {
5201 static struct pointer_set_t *diagnosed;
5202
5203 if (!CLASS_TYPE_P (t))
5204 return;
5205 t = TYPE_MAIN_VARIANT (t);
5206
5207 if (diagnosed == NULL)
5208 diagnosed = pointer_set_create ();
5209 if (pointer_set_insert (diagnosed, t) != 0)
5210 /* Already explained. */
5211 return;
5212
5213 inform (0, "%q+T is not literal because:", t);
5214 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
5215 inform (0, " %q+T has a non-trivial destructor", t);
5216 else if (CLASSTYPE_NON_AGGREGATE (t)
5217 && !TYPE_HAS_TRIVIAL_DFLT (t)
5218 && !TYPE_HAS_CONSTEXPR_CTOR (t))
5219 {
5220 inform (0, " %q+T is not an aggregate, does not have a trivial "
5221 "default constructor, and has no constexpr constructor that "
5222 "is not a copy or move constructor", t);
5223 if (TYPE_HAS_DEFAULT_CONSTRUCTOR (t)
5224 && !type_has_user_provided_default_constructor (t))
5225 {
5226 /* Note that we can't simply call locate_ctor because when the
5227 constructor is deleted it just returns NULL_TREE. */
5228 tree fns;
5229 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
5230 {
5231 tree fn = OVL_CURRENT (fns);
5232 tree parms = TYPE_ARG_TYPES (TREE_TYPE (fn));
5233
5234 parms = skip_artificial_parms_for (fn, parms);
5235
5236 if (sufficient_parms_p (parms))
5237 {
5238 if (DECL_DELETED_FN (fn))
5239 maybe_explain_implicit_delete (fn);
5240 else
5241 explain_invalid_constexpr_fn (fn);
5242 break;
5243 }
5244 }
5245 }
5246 }
5247 else
5248 {
5249 tree binfo, base_binfo, field; int i;
5250 for (binfo = TYPE_BINFO (t), i = 0;
5251 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
5252 {
5253 tree basetype = TREE_TYPE (base_binfo);
5254 if (!CLASSTYPE_LITERAL_P (basetype))
5255 {
5256 inform (0, " base class %qT of %q+T is non-literal",
5257 basetype, t);
5258 explain_non_literal_class (basetype);
5259 return;
5260 }
5261 }
5262 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5263 {
5264 tree ftype;
5265 if (TREE_CODE (field) != FIELD_DECL)
5266 continue;
5267 ftype = TREE_TYPE (field);
5268 if (!literal_type_p (ftype))
5269 {
5270 inform (0, " non-static data member %q+D has "
5271 "non-literal type", field);
5272 if (CLASS_TYPE_P (ftype))
5273 explain_non_literal_class (ftype);
5274 }
5275 }
5276 }
5277 }
5278
5279 /* Check the validity of the bases and members declared in T. Add any
5280 implicitly-generated functions (like copy-constructors and
5281 assignment operators). Compute various flag bits (like
5282 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
5283 level: i.e., independently of the ABI in use. */
5284
5285 static void
check_bases_and_members(tree t)5286 check_bases_and_members (tree t)
5287 {
5288 /* Nonzero if the implicitly generated copy constructor should take
5289 a non-const reference argument. */
5290 int cant_have_const_ctor;
5291 /* Nonzero if the implicitly generated assignment operator
5292 should take a non-const reference argument. */
5293 int no_const_asn_ref;
5294 tree access_decls;
5295 bool saved_complex_asn_ref;
5296 bool saved_nontrivial_dtor;
5297 tree fn;
5298
5299 /* By default, we use const reference arguments and generate default
5300 constructors. */
5301 cant_have_const_ctor = 0;
5302 no_const_asn_ref = 0;
5303
5304 /* Check all the base-classes. */
5305 check_bases (t, &cant_have_const_ctor,
5306 &no_const_asn_ref);
5307
5308 /* Deduce noexcept on destructors. This needs to happen after we've set
5309 triviality flags appropriately for our bases. */
5310 if (cxx_dialect >= cxx0x)
5311 deduce_noexcept_on_destructors (t);
5312
5313 /* Check all the method declarations. */
5314 check_methods (t);
5315
5316 /* Save the initial values of these flags which only indicate whether
5317 or not the class has user-provided functions. As we analyze the
5318 bases and members we can set these flags for other reasons. */
5319 saved_complex_asn_ref = TYPE_HAS_COMPLEX_COPY_ASSIGN (t);
5320 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
5321
5322 /* Check all the data member declarations. We cannot call
5323 check_field_decls until we have called check_bases check_methods,
5324 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
5325 being set appropriately. */
5326 check_field_decls (t, &access_decls,
5327 &cant_have_const_ctor,
5328 &no_const_asn_ref);
5329
5330 /* A nearly-empty class has to be vptr-containing; a nearly empty
5331 class contains just a vptr. */
5332 if (!TYPE_CONTAINS_VPTR_P (t))
5333 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
5334
5335 /* Do some bookkeeping that will guide the generation of implicitly
5336 declared member functions. */
5337 TYPE_HAS_COMPLEX_COPY_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t);
5338 TYPE_HAS_COMPLEX_MOVE_CTOR (t) |= TYPE_CONTAINS_VPTR_P (t);
5339 /* We need to call a constructor for this class if it has a
5340 user-provided constructor, or if the default constructor is going
5341 to initialize the vptr. (This is not an if-and-only-if;
5342 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
5343 themselves need constructing.) */
5344 TYPE_NEEDS_CONSTRUCTING (t)
5345 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t));
5346 /* [dcl.init.aggr]
5347
5348 An aggregate is an array or a class with no user-provided
5349 constructors ... and no virtual functions.
5350
5351 Again, other conditions for being an aggregate are checked
5352 elsewhere. */
5353 CLASSTYPE_NON_AGGREGATE (t)
5354 |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t));
5355 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
5356 retain the old definition internally for ABI reasons. */
5357 CLASSTYPE_NON_LAYOUT_POD_P (t)
5358 |= (CLASSTYPE_NON_AGGREGATE (t)
5359 || saved_nontrivial_dtor || saved_complex_asn_ref);
5360 CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t);
5361 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t);
5362 TYPE_HAS_COMPLEX_MOVE_ASSIGN (t) |= TYPE_CONTAINS_VPTR_P (t);
5363 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
5364
5365 /* If the class has no user-declared constructor, but does have
5366 non-static const or reference data members that can never be
5367 initialized, issue a warning. */
5368 if (warn_uninitialized
5369 /* Classes with user-declared constructors are presumed to
5370 initialize these members. */
5371 && !TYPE_HAS_USER_CONSTRUCTOR (t)
5372 /* Aggregates can be initialized with brace-enclosed
5373 initializers. */
5374 && CLASSTYPE_NON_AGGREGATE (t))
5375 {
5376 tree field;
5377
5378 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
5379 {
5380 tree type;
5381
5382 if (TREE_CODE (field) != FIELD_DECL
5383 || DECL_INITIAL (field) != NULL_TREE)
5384 continue;
5385
5386 type = TREE_TYPE (field);
5387 if (TREE_CODE (type) == REFERENCE_TYPE)
5388 warning (OPT_Wuninitialized, "non-static reference %q+#D "
5389 "in class without a constructor", field);
5390 else if (CP_TYPE_CONST_P (type)
5391 && (!CLASS_TYPE_P (type)
5392 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type)))
5393 warning (OPT_Wuninitialized, "non-static const member %q+#D "
5394 "in class without a constructor", field);
5395 }
5396 }
5397
5398 /* Synthesize any needed methods. */
5399 add_implicitly_declared_members (t, &access_decls,
5400 cant_have_const_ctor,
5401 no_const_asn_ref);
5402
5403 /* Check defaulted declarations here so we have cant_have_const_ctor
5404 and don't need to worry about clones. */
5405 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn))
5406 if (!DECL_ARTIFICIAL (fn) && DECL_DEFAULTED_IN_CLASS_P (fn))
5407 {
5408 int copy = copy_fn_p (fn);
5409 if (copy > 0)
5410 {
5411 bool imp_const_p
5412 = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor
5413 : !no_const_asn_ref);
5414 bool fn_const_p = (copy == 2);
5415
5416 if (fn_const_p && !imp_const_p)
5417 /* If the function is defaulted outside the class, we just
5418 give the synthesis error. */
5419 error ("%q+D declared to take const reference, but implicit "
5420 "declaration would take non-const", fn);
5421 }
5422 defaulted_late_check (fn);
5423 }
5424
5425 if (LAMBDA_TYPE_P (t))
5426 {
5427 /* "The closure type associated with a lambda-expression has a deleted
5428 default constructor and a deleted copy assignment operator." */
5429 TYPE_NEEDS_CONSTRUCTING (t) = 1;
5430 TYPE_HAS_COMPLEX_DFLT (t) = 1;
5431 TYPE_HAS_COMPLEX_COPY_ASSIGN (t) = 1;
5432 CLASSTYPE_LAZY_MOVE_ASSIGN (t) = 0;
5433
5434 /* "This class type is not an aggregate." */
5435 CLASSTYPE_NON_AGGREGATE (t) = 1;
5436 }
5437
5438 /* Compute the 'literal type' property before we
5439 do anything with non-static member functions. */
5440 finalize_literal_type_property (t);
5441
5442 /* Create the in-charge and not-in-charge variants of constructors
5443 and destructors. */
5444 clone_constructors_and_destructors (t);
5445
5446 /* Process the using-declarations. */
5447 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
5448 handle_using_decl (TREE_VALUE (access_decls), t);
5449
5450 /* Build and sort the CLASSTYPE_METHOD_VEC. */
5451 finish_struct_methods (t);
5452
5453 /* Figure out whether or not we will need a cookie when dynamically
5454 allocating an array of this type. */
5455 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
5456 = type_requires_array_cookie (t);
5457 }
5458
5459 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
5460 accordingly. If a new vfield was created (because T doesn't have a
5461 primary base class), then the newly created field is returned. It
5462 is not added to the TYPE_FIELDS list; it is the caller's
5463 responsibility to do that. Accumulate declared virtual functions
5464 on VIRTUALS_P. */
5465
5466 static tree
create_vtable_ptr(tree t,tree * virtuals_p)5467 create_vtable_ptr (tree t, tree* virtuals_p)
5468 {
5469 tree fn;
5470
5471 /* Collect the virtual functions declared in T. */
5472 for (fn = TYPE_METHODS (t); fn; fn = DECL_CHAIN (fn))
5473 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
5474 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
5475 {
5476 tree new_virtual = make_node (TREE_LIST);
5477
5478 BV_FN (new_virtual) = fn;
5479 BV_DELTA (new_virtual) = integer_zero_node;
5480 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
5481
5482 TREE_CHAIN (new_virtual) = *virtuals_p;
5483 *virtuals_p = new_virtual;
5484 }
5485
5486 /* If we couldn't find an appropriate base class, create a new field
5487 here. Even if there weren't any new virtual functions, we might need a
5488 new virtual function table if we're supposed to include vptrs in
5489 all classes that need them. */
5490 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
5491 {
5492 /* We build this decl with vtbl_ptr_type_node, which is a
5493 `vtable_entry_type*'. It might seem more precise to use
5494 `vtable_entry_type (*)[N]' where N is the number of virtual
5495 functions. However, that would require the vtable pointer in
5496 base classes to have a different type than the vtable pointer
5497 in derived classes. We could make that happen, but that
5498 still wouldn't solve all the problems. In particular, the
5499 type-based alias analysis code would decide that assignments
5500 to the base class vtable pointer can't alias assignments to
5501 the derived class vtable pointer, since they have different
5502 types. Thus, in a derived class destructor, where the base
5503 class constructor was inlined, we could generate bad code for
5504 setting up the vtable pointer.
5505
5506 Therefore, we use one type for all vtable pointers. We still
5507 use a type-correct type; it's just doesn't indicate the array
5508 bounds. That's better than using `void*' or some such; it's
5509 cleaner, and it let's the alias analysis code know that these
5510 stores cannot alias stores to void*! */
5511 tree field;
5512
5513 field = build_decl (input_location,
5514 FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
5515 DECL_VIRTUAL_P (field) = 1;
5516 DECL_ARTIFICIAL (field) = 1;
5517 DECL_FIELD_CONTEXT (field) = t;
5518 DECL_FCONTEXT (field) = t;
5519 if (TYPE_PACKED (t))
5520 DECL_PACKED (field) = 1;
5521
5522 TYPE_VFIELD (t) = field;
5523
5524 /* This class is non-empty. */
5525 CLASSTYPE_EMPTY_P (t) = 0;
5526
5527 return field;
5528 }
5529
5530 return NULL_TREE;
5531 }
5532
5533 /* Add OFFSET to all base types of BINFO which is a base in the
5534 hierarchy dominated by T.
5535
5536 OFFSET, which is a type offset, is number of bytes. */
5537
5538 static void
propagate_binfo_offsets(tree binfo,tree offset)5539 propagate_binfo_offsets (tree binfo, tree offset)
5540 {
5541 int i;
5542 tree primary_binfo;
5543 tree base_binfo;
5544
5545 /* Update BINFO's offset. */
5546 BINFO_OFFSET (binfo)
5547 = convert (sizetype,
5548 size_binop (PLUS_EXPR,
5549 convert (ssizetype, BINFO_OFFSET (binfo)),
5550 offset));
5551
5552 /* Find the primary base class. */
5553 primary_binfo = get_primary_binfo (binfo);
5554
5555 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
5556 propagate_binfo_offsets (primary_binfo, offset);
5557
5558 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
5559 downwards. */
5560 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
5561 {
5562 /* Don't do the primary base twice. */
5563 if (base_binfo == primary_binfo)
5564 continue;
5565
5566 if (BINFO_VIRTUAL_P (base_binfo))
5567 continue;
5568
5569 propagate_binfo_offsets (base_binfo, offset);
5570 }
5571 }
5572
5573 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
5574 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
5575 empty subobjects of T. */
5576
5577 static void
layout_virtual_bases(record_layout_info rli,splay_tree offsets)5578 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
5579 {
5580 tree vbase;
5581 tree t = rli->t;
5582 bool first_vbase = true;
5583 tree *next_field;
5584
5585 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
5586 return;
5587
5588 if (!abi_version_at_least(2))
5589 {
5590 /* In G++ 3.2, we incorrectly rounded the size before laying out
5591 the virtual bases. */
5592 finish_record_layout (rli, /*free_p=*/false);
5593 #ifdef STRUCTURE_SIZE_BOUNDARY
5594 /* Packed structures don't need to have minimum size. */
5595 if (! TYPE_PACKED (t))
5596 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
5597 #endif
5598 rli->offset = TYPE_SIZE_UNIT (t);
5599 rli->bitpos = bitsize_zero_node;
5600 rli->record_align = TYPE_ALIGN (t);
5601 }
5602
5603 /* Find the last field. The artificial fields created for virtual
5604 bases will go after the last extant field to date. */
5605 next_field = &TYPE_FIELDS (t);
5606 while (*next_field)
5607 next_field = &DECL_CHAIN (*next_field);
5608
5609 /* Go through the virtual bases, allocating space for each virtual
5610 base that is not already a primary base class. These are
5611 allocated in inheritance graph order. */
5612 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
5613 {
5614 if (!BINFO_VIRTUAL_P (vbase))
5615 continue;
5616
5617 if (!BINFO_PRIMARY_P (vbase))
5618 {
5619 tree basetype = TREE_TYPE (vbase);
5620
5621 /* This virtual base is not a primary base of any class in the
5622 hierarchy, so we have to add space for it. */
5623 next_field = build_base_field (rli, vbase,
5624 offsets, next_field);
5625
5626 /* If the first virtual base might have been placed at a
5627 lower address, had we started from CLASSTYPE_SIZE, rather
5628 than TYPE_SIZE, issue a warning. There can be both false
5629 positives and false negatives from this warning in rare
5630 cases; to deal with all the possibilities would probably
5631 require performing both layout algorithms and comparing
5632 the results which is not particularly tractable. */
5633 if (warn_abi
5634 && first_vbase
5635 && (tree_int_cst_lt
5636 (size_binop (CEIL_DIV_EXPR,
5637 round_up_loc (input_location,
5638 CLASSTYPE_SIZE (t),
5639 CLASSTYPE_ALIGN (basetype)),
5640 bitsize_unit_node),
5641 BINFO_OFFSET (vbase))))
5642 warning (OPT_Wabi,
5643 "offset of virtual base %qT is not ABI-compliant and "
5644 "may change in a future version of GCC",
5645 basetype);
5646
5647 first_vbase = false;
5648 }
5649 }
5650 }
5651
5652 /* Returns the offset of the byte just past the end of the base class
5653 BINFO. */
5654
5655 static tree
end_of_base(tree binfo)5656 end_of_base (tree binfo)
5657 {
5658 tree size;
5659
5660 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo)))
5661 size = TYPE_SIZE_UNIT (char_type_node);
5662 else if (is_empty_class (BINFO_TYPE (binfo)))
5663 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
5664 allocate some space for it. It cannot have virtual bases, so
5665 TYPE_SIZE_UNIT is fine. */
5666 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
5667 else
5668 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
5669
5670 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
5671 }
5672
5673 /* Returns the offset of the byte just past the end of the base class
5674 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
5675 only non-virtual bases are included. */
5676
5677 static tree
end_of_class(tree t,int include_virtuals_p)5678 end_of_class (tree t, int include_virtuals_p)
5679 {
5680 tree result = size_zero_node;
5681 vec<tree, va_gc> *vbases;
5682 tree binfo;
5683 tree base_binfo;
5684 tree offset;
5685 int i;
5686
5687 for (binfo = TYPE_BINFO (t), i = 0;
5688 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
5689 {
5690 if (!include_virtuals_p
5691 && BINFO_VIRTUAL_P (base_binfo)
5692 && (!BINFO_PRIMARY_P (base_binfo)
5693 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
5694 continue;
5695
5696 offset = end_of_base (base_binfo);
5697 if (INT_CST_LT_UNSIGNED (result, offset))
5698 result = offset;
5699 }
5700
5701 /* G++ 3.2 did not check indirect virtual bases. */
5702 if (abi_version_at_least (2) && include_virtuals_p)
5703 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
5704 vec_safe_iterate (vbases, i, &base_binfo); i++)
5705 {
5706 offset = end_of_base (base_binfo);
5707 if (INT_CST_LT_UNSIGNED (result, offset))
5708 result = offset;
5709 }
5710
5711 return result;
5712 }
5713
5714 /* Warn about bases of T that are inaccessible because they are
5715 ambiguous. For example:
5716
5717 struct S {};
5718 struct T : public S {};
5719 struct U : public S, public T {};
5720
5721 Here, `(S*) new U' is not allowed because there are two `S'
5722 subobjects of U. */
5723
5724 static void
warn_about_ambiguous_bases(tree t)5725 warn_about_ambiguous_bases (tree t)
5726 {
5727 int i;
5728 vec<tree, va_gc> *vbases;
5729 tree basetype;
5730 tree binfo;
5731 tree base_binfo;
5732
5733 /* If there are no repeated bases, nothing can be ambiguous. */
5734 if (!CLASSTYPE_REPEATED_BASE_P (t))
5735 return;
5736
5737 /* Check direct bases. */
5738 for (binfo = TYPE_BINFO (t), i = 0;
5739 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
5740 {
5741 basetype = BINFO_TYPE (base_binfo);
5742
5743 if (!uniquely_derived_from_p (basetype, t))
5744 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
5745 basetype, t);
5746 }
5747
5748 /* Check for ambiguous virtual bases. */
5749 if (extra_warnings)
5750 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
5751 vec_safe_iterate (vbases, i, &binfo); i++)
5752 {
5753 basetype = BINFO_TYPE (binfo);
5754
5755 if (!uniquely_derived_from_p (basetype, t))
5756 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due "
5757 "to ambiguity", basetype, t);
5758 }
5759 }
5760
5761 /* Compare two INTEGER_CSTs K1 and K2. */
5762
5763 static int
splay_tree_compare_integer_csts(splay_tree_key k1,splay_tree_key k2)5764 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
5765 {
5766 return tree_int_cst_compare ((tree) k1, (tree) k2);
5767 }
5768
5769 /* Increase the size indicated in RLI to account for empty classes
5770 that are "off the end" of the class. */
5771
5772 static void
include_empty_classes(record_layout_info rli)5773 include_empty_classes (record_layout_info rli)
5774 {
5775 tree eoc;
5776 tree rli_size;
5777
5778 /* It might be the case that we grew the class to allocate a
5779 zero-sized base class. That won't be reflected in RLI, yet,
5780 because we are willing to overlay multiple bases at the same
5781 offset. However, now we need to make sure that RLI is big enough
5782 to reflect the entire class. */
5783 eoc = end_of_class (rli->t,
5784 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
5785 rli_size = rli_size_unit_so_far (rli);
5786 if (TREE_CODE (rli_size) == INTEGER_CST
5787 && INT_CST_LT_UNSIGNED (rli_size, eoc))
5788 {
5789 if (!abi_version_at_least (2))
5790 /* In version 1 of the ABI, the size of a class that ends with
5791 a bitfield was not rounded up to a whole multiple of a
5792 byte. Because rli_size_unit_so_far returns only the number
5793 of fully allocated bytes, any extra bits were not included
5794 in the size. */
5795 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
5796 else
5797 /* The size should have been rounded to a whole byte. */
5798 gcc_assert (tree_int_cst_equal
5799 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
5800 rli->bitpos
5801 = size_binop (PLUS_EXPR,
5802 rli->bitpos,
5803 size_binop (MULT_EXPR,
5804 convert (bitsizetype,
5805 size_binop (MINUS_EXPR,
5806 eoc, rli_size)),
5807 bitsize_int (BITS_PER_UNIT)));
5808 normalize_rli (rli);
5809 }
5810 }
5811
5812 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
5813 BINFO_OFFSETs for all of the base-classes. Position the vtable
5814 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
5815
5816 static void
layout_class_type(tree t,tree * virtuals_p)5817 layout_class_type (tree t, tree *virtuals_p)
5818 {
5819 tree non_static_data_members;
5820 tree field;
5821 tree vptr;
5822 record_layout_info rli;
5823 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
5824 types that appear at that offset. */
5825 splay_tree empty_base_offsets;
5826 /* True if the last field layed out was a bit-field. */
5827 bool last_field_was_bitfield = false;
5828 /* The location at which the next field should be inserted. */
5829 tree *next_field;
5830 /* T, as a base class. */
5831 tree base_t;
5832
5833 /* Keep track of the first non-static data member. */
5834 non_static_data_members = TYPE_FIELDS (t);
5835
5836 /* Start laying out the record. */
5837 rli = start_record_layout (t);
5838
5839 /* Mark all the primary bases in the hierarchy. */
5840 determine_primary_bases (t);
5841
5842 /* Create a pointer to our virtual function table. */
5843 vptr = create_vtable_ptr (t, virtuals_p);
5844
5845 /* The vptr is always the first thing in the class. */
5846 if (vptr)
5847 {
5848 DECL_CHAIN (vptr) = TYPE_FIELDS (t);
5849 TYPE_FIELDS (t) = vptr;
5850 next_field = &DECL_CHAIN (vptr);
5851 place_field (rli, vptr);
5852 }
5853 else
5854 next_field = &TYPE_FIELDS (t);
5855
5856 /* Build FIELD_DECLs for all of the non-virtual base-types. */
5857 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
5858 NULL, NULL);
5859 build_base_fields (rli, empty_base_offsets, next_field);
5860
5861 /* Layout the non-static data members. */
5862 for (field = non_static_data_members; field; field = DECL_CHAIN (field))
5863 {
5864 tree type;
5865 tree padding;
5866
5867 /* We still pass things that aren't non-static data members to
5868 the back end, in case it wants to do something with them. */
5869 if (TREE_CODE (field) != FIELD_DECL)
5870 {
5871 place_field (rli, field);
5872 /* If the static data member has incomplete type, keep track
5873 of it so that it can be completed later. (The handling
5874 of pending statics in finish_record_layout is
5875 insufficient; consider:
5876
5877 struct S1;
5878 struct S2 { static S1 s1; };
5879
5880 At this point, finish_record_layout will be called, but
5881 S1 is still incomplete.) */
5882 if (TREE_CODE (field) == VAR_DECL)
5883 {
5884 maybe_register_incomplete_var (field);
5885 /* The visibility of static data members is determined
5886 at their point of declaration, not their point of
5887 definition. */
5888 determine_visibility (field);
5889 }
5890 continue;
5891 }
5892
5893 type = TREE_TYPE (field);
5894 if (type == error_mark_node)
5895 continue;
5896
5897 padding = NULL_TREE;
5898
5899 /* If this field is a bit-field whose width is greater than its
5900 type, then there are some special rules for allocating
5901 it. */
5902 if (DECL_C_BIT_FIELD (field)
5903 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
5904 {
5905 unsigned int itk;
5906 tree integer_type;
5907 bool was_unnamed_p = false;
5908 /* We must allocate the bits as if suitably aligned for the
5909 longest integer type that fits in this many bits. type
5910 of the field. Then, we are supposed to use the left over
5911 bits as additional padding. */
5912 for (itk = itk_char; itk != itk_none; ++itk)
5913 if (integer_types[itk] != NULL_TREE
5914 && (INT_CST_LT (size_int (MAX_FIXED_MODE_SIZE),
5915 TYPE_SIZE (integer_types[itk]))
5916 || INT_CST_LT (DECL_SIZE (field),
5917 TYPE_SIZE (integer_types[itk]))))
5918 break;
5919
5920 /* ITK now indicates a type that is too large for the
5921 field. We have to back up by one to find the largest
5922 type that fits. */
5923 do
5924 {
5925 --itk;
5926 integer_type = integer_types[itk];
5927 } while (itk > 0 && integer_type == NULL_TREE);
5928
5929 /* Figure out how much additional padding is required. GCC
5930 3.2 always created a padding field, even if it had zero
5931 width. */
5932 if (!abi_version_at_least (2)
5933 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
5934 {
5935 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
5936 /* In a union, the padding field must have the full width
5937 of the bit-field; all fields start at offset zero. */
5938 padding = DECL_SIZE (field);
5939 else
5940 {
5941 if (TREE_CODE (t) == UNION_TYPE)
5942 warning (OPT_Wabi, "size assigned to %qT may not be "
5943 "ABI-compliant and may change in a future "
5944 "version of GCC",
5945 t);
5946 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
5947 TYPE_SIZE (integer_type));
5948 }
5949 }
5950 #ifdef PCC_BITFIELD_TYPE_MATTERS
5951 /* An unnamed bitfield does not normally affect the
5952 alignment of the containing class on a target where
5953 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
5954 make any exceptions for unnamed bitfields when the
5955 bitfields are longer than their types. Therefore, we
5956 temporarily give the field a name. */
5957 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
5958 {
5959 was_unnamed_p = true;
5960 DECL_NAME (field) = make_anon_name ();
5961 }
5962 #endif
5963 DECL_SIZE (field) = TYPE_SIZE (integer_type);
5964 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
5965 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
5966 layout_nonempty_base_or_field (rli, field, NULL_TREE,
5967 empty_base_offsets);
5968 if (was_unnamed_p)
5969 DECL_NAME (field) = NULL_TREE;
5970 /* Now that layout has been performed, set the size of the
5971 field to the size of its declared type; the rest of the
5972 field is effectively invisible. */
5973 DECL_SIZE (field) = TYPE_SIZE (type);
5974 /* We must also reset the DECL_MODE of the field. */
5975 if (abi_version_at_least (2))
5976 DECL_MODE (field) = TYPE_MODE (type);
5977 else if (warn_abi
5978 && DECL_MODE (field) != TYPE_MODE (type))
5979 /* Versions of G++ before G++ 3.4 did not reset the
5980 DECL_MODE. */
5981 warning (OPT_Wabi,
5982 "the offset of %qD may not be ABI-compliant and may "
5983 "change in a future version of GCC", field);
5984 }
5985 else
5986 layout_nonempty_base_or_field (rli, field, NULL_TREE,
5987 empty_base_offsets);
5988
5989 /* Remember the location of any empty classes in FIELD. */
5990 if (abi_version_at_least (2))
5991 record_subobject_offsets (TREE_TYPE (field),
5992 byte_position(field),
5993 empty_base_offsets,
5994 /*is_data_member=*/true);
5995
5996 /* If a bit-field does not immediately follow another bit-field,
5997 and yet it starts in the middle of a byte, we have failed to
5998 comply with the ABI. */
5999 if (warn_abi
6000 && DECL_C_BIT_FIELD (field)
6001 /* The TREE_NO_WARNING flag gets set by Objective-C when
6002 laying out an Objective-C class. The ObjC ABI differs
6003 from the C++ ABI, and so we do not want a warning
6004 here. */
6005 && !TREE_NO_WARNING (field)
6006 && !last_field_was_bitfield
6007 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
6008 DECL_FIELD_BIT_OFFSET (field),
6009 bitsize_unit_node)))
6010 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
6011 "change in a future version of GCC", field);
6012
6013 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
6014 offset of the field. */
6015 if (warn_abi
6016 && !abi_version_at_least (2)
6017 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
6018 byte_position (field))
6019 && contains_empty_class_p (TREE_TYPE (field)))
6020 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
6021 "classes to be placed at different locations in a "
6022 "future version of GCC", field);
6023
6024 /* The middle end uses the type of expressions to determine the
6025 possible range of expression values. In order to optimize
6026 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
6027 must be made aware of the width of "i", via its type.
6028
6029 Because C++ does not have integer types of arbitrary width,
6030 we must (for the purposes of the front end) convert from the
6031 type assigned here to the declared type of the bitfield
6032 whenever a bitfield expression is used as an rvalue.
6033 Similarly, when assigning a value to a bitfield, the value
6034 must be converted to the type given the bitfield here. */
6035 if (DECL_C_BIT_FIELD (field))
6036 {
6037 unsigned HOST_WIDE_INT width;
6038 tree ftype = TREE_TYPE (field);
6039 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
6040 if (width != TYPE_PRECISION (ftype))
6041 {
6042 TREE_TYPE (field)
6043 = c_build_bitfield_integer_type (width,
6044 TYPE_UNSIGNED (ftype));
6045 TREE_TYPE (field)
6046 = cp_build_qualified_type (TREE_TYPE (field),
6047 cp_type_quals (ftype));
6048 }
6049 }
6050
6051 /* If we needed additional padding after this field, add it
6052 now. */
6053 if (padding)
6054 {
6055 tree padding_field;
6056
6057 padding_field = build_decl (input_location,
6058 FIELD_DECL,
6059 NULL_TREE,
6060 char_type_node);
6061 DECL_BIT_FIELD (padding_field) = 1;
6062 DECL_SIZE (padding_field) = padding;
6063 DECL_CONTEXT (padding_field) = t;
6064 DECL_ARTIFICIAL (padding_field) = 1;
6065 DECL_IGNORED_P (padding_field) = 1;
6066 layout_nonempty_base_or_field (rli, padding_field,
6067 NULL_TREE,
6068 empty_base_offsets);
6069 }
6070
6071 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
6072 }
6073
6074 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
6075 {
6076 /* Make sure that we are on a byte boundary so that the size of
6077 the class without virtual bases will always be a round number
6078 of bytes. */
6079 rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT);
6080 normalize_rli (rli);
6081 }
6082
6083 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
6084 padding. */
6085 if (!abi_version_at_least (2))
6086 include_empty_classes(rli);
6087
6088 /* Delete all zero-width bit-fields from the list of fields. Now
6089 that the type is laid out they are no longer important. */
6090 remove_zero_width_bit_fields (t);
6091
6092 /* Create the version of T used for virtual bases. We do not use
6093 make_class_type for this version; this is an artificial type. For
6094 a POD type, we just reuse T. */
6095 if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t))
6096 {
6097 base_t = make_node (TREE_CODE (t));
6098
6099 /* Set the size and alignment for the new type. In G++ 3.2, all
6100 empty classes were considered to have size zero when used as
6101 base classes. */
6102 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
6103 {
6104 TYPE_SIZE (base_t) = bitsize_zero_node;
6105 TYPE_SIZE_UNIT (base_t) = size_zero_node;
6106 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
6107 warning (OPT_Wabi,
6108 "layout of classes derived from empty class %qT "
6109 "may change in a future version of GCC",
6110 t);
6111 }
6112 else
6113 {
6114 tree eoc;
6115
6116 /* If the ABI version is not at least two, and the last
6117 field was a bit-field, RLI may not be on a byte
6118 boundary. In particular, rli_size_unit_so_far might
6119 indicate the last complete byte, while rli_size_so_far
6120 indicates the total number of bits used. Therefore,
6121 rli_size_so_far, rather than rli_size_unit_so_far, is
6122 used to compute TYPE_SIZE_UNIT. */
6123 eoc = end_of_class (t, /*include_virtuals_p=*/0);
6124 TYPE_SIZE_UNIT (base_t)
6125 = size_binop (MAX_EXPR,
6126 convert (sizetype,
6127 size_binop (CEIL_DIV_EXPR,
6128 rli_size_so_far (rli),
6129 bitsize_int (BITS_PER_UNIT))),
6130 eoc);
6131 TYPE_SIZE (base_t)
6132 = size_binop (MAX_EXPR,
6133 rli_size_so_far (rli),
6134 size_binop (MULT_EXPR,
6135 convert (bitsizetype, eoc),
6136 bitsize_int (BITS_PER_UNIT)));
6137 }
6138 TYPE_ALIGN (base_t) = rli->record_align;
6139 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
6140
6141 /* Copy the fields from T. */
6142 next_field = &TYPE_FIELDS (base_t);
6143 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
6144 if (TREE_CODE (field) == FIELD_DECL)
6145 {
6146 *next_field = build_decl (input_location,
6147 FIELD_DECL,
6148 DECL_NAME (field),
6149 TREE_TYPE (field));
6150 DECL_CONTEXT (*next_field) = base_t;
6151 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
6152 DECL_FIELD_BIT_OFFSET (*next_field)
6153 = DECL_FIELD_BIT_OFFSET (field);
6154 DECL_SIZE (*next_field) = DECL_SIZE (field);
6155 DECL_MODE (*next_field) = DECL_MODE (field);
6156 next_field = &DECL_CHAIN (*next_field);
6157 }
6158
6159 /* Record the base version of the type. */
6160 CLASSTYPE_AS_BASE (t) = base_t;
6161 TYPE_CONTEXT (base_t) = t;
6162 }
6163 else
6164 CLASSTYPE_AS_BASE (t) = t;
6165
6166 /* Every empty class contains an empty class. */
6167 if (CLASSTYPE_EMPTY_P (t))
6168 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
6169
6170 /* Set the TYPE_DECL for this type to contain the right
6171 value for DECL_OFFSET, so that we can use it as part
6172 of a COMPONENT_REF for multiple inheritance. */
6173 layout_decl (TYPE_MAIN_DECL (t), 0);
6174
6175 /* Now fix up any virtual base class types that we left lying
6176 around. We must get these done before we try to lay out the
6177 virtual function table. As a side-effect, this will remove the
6178 base subobject fields. */
6179 layout_virtual_bases (rli, empty_base_offsets);
6180
6181 /* Make sure that empty classes are reflected in RLI at this
6182 point. */
6183 include_empty_classes(rli);
6184
6185 /* Make sure not to create any structures with zero size. */
6186 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
6187 place_field (rli,
6188 build_decl (input_location,
6189 FIELD_DECL, NULL_TREE, char_type_node));
6190
6191 /* If this is a non-POD, declaring it packed makes a difference to how it
6192 can be used as a field; don't let finalize_record_size undo it. */
6193 if (TYPE_PACKED (t) && !layout_pod_type_p (t))
6194 rli->packed_maybe_necessary = true;
6195
6196 /* Let the back end lay out the type. */
6197 finish_record_layout (rli, /*free_p=*/true);
6198
6199 /* Warn about bases that can't be talked about due to ambiguity. */
6200 warn_about_ambiguous_bases (t);
6201
6202 /* Now that we're done with layout, give the base fields the real types. */
6203 for (field = TYPE_FIELDS (t); field; field = DECL_CHAIN (field))
6204 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
6205 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
6206
6207 /* Clean up. */
6208 splay_tree_delete (empty_base_offsets);
6209
6210 if (CLASSTYPE_EMPTY_P (t)
6211 && tree_int_cst_lt (sizeof_biggest_empty_class,
6212 TYPE_SIZE_UNIT (t)))
6213 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
6214 }
6215
6216 /* Determine the "key method" for the class type indicated by TYPE,
6217 and set CLASSTYPE_KEY_METHOD accordingly. */
6218
6219 void
determine_key_method(tree type)6220 determine_key_method (tree type)
6221 {
6222 tree method;
6223
6224 if (TYPE_FOR_JAVA (type)
6225 || processing_template_decl
6226 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
6227 || CLASSTYPE_INTERFACE_KNOWN (type))
6228 return;
6229
6230 /* The key method is the first non-pure virtual function that is not
6231 inline at the point of class definition. On some targets the
6232 key function may not be inline; those targets should not call
6233 this function until the end of the translation unit. */
6234 for (method = TYPE_METHODS (type); method != NULL_TREE;
6235 method = DECL_CHAIN (method))
6236 if (DECL_VINDEX (method) != NULL_TREE
6237 && ! DECL_DECLARED_INLINE_P (method)
6238 && ! DECL_PURE_VIRTUAL_P (method))
6239 {
6240 CLASSTYPE_KEY_METHOD (type) = method;
6241 break;
6242 }
6243
6244 return;
6245 }
6246
6247
6248 /* Allocate and return an instance of struct sorted_fields_type with
6249 N fields. */
6250
6251 static struct sorted_fields_type *
sorted_fields_type_new(int n)6252 sorted_fields_type_new (int n)
6253 {
6254 struct sorted_fields_type *sft;
6255 sft = ggc_alloc_sorted_fields_type (sizeof (struct sorted_fields_type)
6256 + n * sizeof (tree));
6257 sft->len = n;
6258
6259 return sft;
6260 }
6261
6262
6263 /* Perform processing required when the definition of T (a class type)
6264 is complete. */
6265
6266 void
finish_struct_1(tree t)6267 finish_struct_1 (tree t)
6268 {
6269 tree x;
6270 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
6271 tree virtuals = NULL_TREE;
6272
6273 if (COMPLETE_TYPE_P (t))
6274 {
6275 gcc_assert (MAYBE_CLASS_TYPE_P (t));
6276 error ("redefinition of %q#T", t);
6277 popclass ();
6278 return;
6279 }
6280
6281 /* If this type was previously laid out as a forward reference,
6282 make sure we lay it out again. */
6283 TYPE_SIZE (t) = NULL_TREE;
6284 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
6285
6286 /* Make assumptions about the class; we'll reset the flags if
6287 necessary. */
6288 CLASSTYPE_EMPTY_P (t) = 1;
6289 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
6290 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
6291 CLASSTYPE_LITERAL_P (t) = true;
6292
6293 /* Do end-of-class semantic processing: checking the validity of the
6294 bases and members and add implicitly generated methods. */
6295 check_bases_and_members (t);
6296
6297 /* Find the key method. */
6298 if (TYPE_CONTAINS_VPTR_P (t))
6299 {
6300 /* The Itanium C++ ABI permits the key method to be chosen when
6301 the class is defined -- even though the key method so
6302 selected may later turn out to be an inline function. On
6303 some systems (such as ARM Symbian OS) the key method cannot
6304 be determined until the end of the translation unit. On such
6305 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
6306 will cause the class to be added to KEYED_CLASSES. Then, in
6307 finish_file we will determine the key method. */
6308 if (targetm.cxx.key_method_may_be_inline ())
6309 determine_key_method (t);
6310
6311 /* If a polymorphic class has no key method, we may emit the vtable
6312 in every translation unit where the class definition appears. */
6313 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
6314 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
6315 }
6316
6317 /* Layout the class itself. */
6318 layout_class_type (t, &virtuals);
6319 if (CLASSTYPE_AS_BASE (t) != t)
6320 /* We use the base type for trivial assignments, and hence it
6321 needs a mode. */
6322 compute_record_mode (CLASSTYPE_AS_BASE (t));
6323
6324 virtuals = modify_all_vtables (t, nreverse (virtuals));
6325
6326 /* If necessary, create the primary vtable for this class. */
6327 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
6328 {
6329 /* We must enter these virtuals into the table. */
6330 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
6331 build_primary_vtable (NULL_TREE, t);
6332 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
6333 /* Here we know enough to change the type of our virtual
6334 function table, but we will wait until later this function. */
6335 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
6336
6337 /* If we're warning about ABI tags, check the types of the new
6338 virtual functions. */
6339 if (warn_abi_tag)
6340 for (tree v = virtuals; v; v = TREE_CHAIN (v))
6341 check_abi_tags (t, TREE_VALUE (v));
6342 }
6343
6344 if (TYPE_CONTAINS_VPTR_P (t))
6345 {
6346 int vindex;
6347 tree fn;
6348
6349 if (BINFO_VTABLE (TYPE_BINFO (t)))
6350 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
6351 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
6352 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
6353
6354 /* Add entries for virtual functions introduced by this class. */
6355 BINFO_VIRTUALS (TYPE_BINFO (t))
6356 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
6357
6358 /* Set DECL_VINDEX for all functions declared in this class. */
6359 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
6360 fn;
6361 fn = TREE_CHAIN (fn),
6362 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
6363 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
6364 {
6365 tree fndecl = BV_FN (fn);
6366
6367 if (DECL_THUNK_P (fndecl))
6368 /* A thunk. We should never be calling this entry directly
6369 from this vtable -- we'd use the entry for the non
6370 thunk base function. */
6371 DECL_VINDEX (fndecl) = NULL_TREE;
6372 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
6373 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
6374 }
6375 }
6376
6377 finish_struct_bits (t);
6378 set_method_tm_attributes (t);
6379
6380 /* Complete the rtl for any static member objects of the type we're
6381 working on. */
6382 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x))
6383 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
6384 && TREE_TYPE (x) != error_mark_node
6385 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
6386 DECL_MODE (x) = TYPE_MODE (t);
6387
6388 /* Done with FIELDS...now decide whether to sort these for
6389 faster lookups later.
6390
6391 We use a small number because most searches fail (succeeding
6392 ultimately as the search bores through the inheritance
6393 hierarchy), and we want this failure to occur quickly. */
6394
6395 insert_into_classtype_sorted_fields (TYPE_FIELDS (t), t, 8);
6396
6397 /* Complain if one of the field types requires lower visibility. */
6398 constrain_class_visibility (t);
6399
6400 /* Make the rtl for any new vtables we have created, and unmark
6401 the base types we marked. */
6402 finish_vtbls (t);
6403
6404 /* Build the VTT for T. */
6405 build_vtt (t);
6406
6407 /* This warning does not make sense for Java classes, since they
6408 cannot have destructors. */
6409 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
6410 {
6411 tree dtor;
6412
6413 dtor = CLASSTYPE_DESTRUCTORS (t);
6414 if (/* An implicitly declared destructor is always public. And,
6415 if it were virtual, we would have created it by now. */
6416 !dtor
6417 || (!DECL_VINDEX (dtor)
6418 && (/* public non-virtual */
6419 (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
6420 || (/* non-public non-virtual with friends */
6421 (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
6422 && (CLASSTYPE_FRIEND_CLASSES (t)
6423 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
6424 warning (OPT_Wnon_virtual_dtor,
6425 "%q#T has virtual functions and accessible"
6426 " non-virtual destructor", t);
6427 }
6428
6429 complete_vars (t);
6430
6431 if (warn_overloaded_virtual)
6432 warn_hidden (t);
6433
6434 /* Class layout, assignment of virtual table slots, etc., is now
6435 complete. Give the back end a chance to tweak the visibility of
6436 the class or perform any other required target modifications. */
6437 targetm.cxx.adjust_class_at_definition (t);
6438
6439 maybe_suppress_debug_info (t);
6440
6441 dump_class_hierarchy (t);
6442
6443 /* Finish debugging output for this type. */
6444 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
6445
6446 if (TYPE_TRANSPARENT_AGGR (t))
6447 {
6448 tree field = first_field (t);
6449 if (field == NULL_TREE || error_operand_p (field))
6450 {
6451 error ("type transparent %q#T does not have any fields", t);
6452 TYPE_TRANSPARENT_AGGR (t) = 0;
6453 }
6454 else if (DECL_ARTIFICIAL (field))
6455 {
6456 if (DECL_FIELD_IS_BASE (field))
6457 error ("type transparent class %qT has base classes", t);
6458 else
6459 {
6460 gcc_checking_assert (DECL_VIRTUAL_P (field));
6461 error ("type transparent class %qT has virtual functions", t);
6462 }
6463 TYPE_TRANSPARENT_AGGR (t) = 0;
6464 }
6465 else if (TYPE_MODE (t) != DECL_MODE (field))
6466 {
6467 error ("type transparent %q#T cannot be made transparent because "
6468 "the type of the first field has a different ABI from the "
6469 "class overall", t);
6470 TYPE_TRANSPARENT_AGGR (t) = 0;
6471 }
6472 }
6473 }
6474
6475 /* Insert FIELDS into T for the sorted case if the FIELDS count is
6476 equal to THRESHOLD or greater than THRESHOLD. */
6477
6478 static void
insert_into_classtype_sorted_fields(tree fields,tree t,int threshold)6479 insert_into_classtype_sorted_fields (tree fields, tree t, int threshold)
6480 {
6481 int n_fields = count_fields (fields);
6482 if (n_fields >= threshold)
6483 {
6484 struct sorted_fields_type *field_vec = sorted_fields_type_new (n_fields);
6485 add_fields_to_record_type (fields, field_vec, 0);
6486 qsort (field_vec->elts, n_fields, sizeof (tree), field_decl_cmp);
6487 CLASSTYPE_SORTED_FIELDS (t) = field_vec;
6488 }
6489 }
6490
6491 /* Insert lately defined enum ENUMTYPE into T for the sorted case. */
6492
6493 void
insert_late_enum_def_into_classtype_sorted_fields(tree enumtype,tree t)6494 insert_late_enum_def_into_classtype_sorted_fields (tree enumtype, tree t)
6495 {
6496 struct sorted_fields_type *sorted_fields = CLASSTYPE_SORTED_FIELDS (t);
6497 if (sorted_fields)
6498 {
6499 int i;
6500 int n_fields
6501 = list_length (TYPE_VALUES (enumtype)) + sorted_fields->len;
6502 struct sorted_fields_type *field_vec = sorted_fields_type_new (n_fields);
6503
6504 for (i = 0; i < sorted_fields->len; ++i)
6505 field_vec->elts[i] = sorted_fields->elts[i];
6506
6507 add_enum_fields_to_record_type (enumtype, field_vec,
6508 sorted_fields->len);
6509 qsort (field_vec->elts, n_fields, sizeof (tree), field_decl_cmp);
6510 CLASSTYPE_SORTED_FIELDS (t) = field_vec;
6511 }
6512 }
6513
6514 /* When T was built up, the member declarations were added in reverse
6515 order. Rearrange them to declaration order. */
6516
6517 void
unreverse_member_declarations(tree t)6518 unreverse_member_declarations (tree t)
6519 {
6520 tree next;
6521 tree prev;
6522 tree x;
6523
6524 /* The following lists are all in reverse order. Put them in
6525 declaration order now. */
6526 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
6527 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
6528
6529 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
6530 reverse order, so we can't just use nreverse. */
6531 prev = NULL_TREE;
6532 for (x = TYPE_FIELDS (t);
6533 x && TREE_CODE (x) != TYPE_DECL;
6534 x = next)
6535 {
6536 next = DECL_CHAIN (x);
6537 DECL_CHAIN (x) = prev;
6538 prev = x;
6539 }
6540 if (prev)
6541 {
6542 DECL_CHAIN (TYPE_FIELDS (t)) = x;
6543 if (prev)
6544 TYPE_FIELDS (t) = prev;
6545 }
6546 }
6547
6548 tree
finish_struct(tree t,tree attributes)6549 finish_struct (tree t, tree attributes)
6550 {
6551 location_t saved_loc = input_location;
6552
6553 /* Now that we've got all the field declarations, reverse everything
6554 as necessary. */
6555 unreverse_member_declarations (t);
6556
6557 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
6558
6559 /* Nadger the current location so that diagnostics point to the start of
6560 the struct, not the end. */
6561 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
6562
6563 if (processing_template_decl)
6564 {
6565 tree x;
6566
6567 finish_struct_methods (t);
6568 TYPE_SIZE (t) = bitsize_zero_node;
6569 TYPE_SIZE_UNIT (t) = size_zero_node;
6570
6571 /* We need to emit an error message if this type was used as a parameter
6572 and it is an abstract type, even if it is a template. We construct
6573 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
6574 account and we call complete_vars with this type, which will check
6575 the PARM_DECLS. Note that while the type is being defined,
6576 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
6577 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
6578 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
6579 for (x = TYPE_METHODS (t); x; x = DECL_CHAIN (x))
6580 if (DECL_PURE_VIRTUAL_P (x))
6581 vec_safe_push (CLASSTYPE_PURE_VIRTUALS (t), x);
6582 complete_vars (t);
6583 /* We need to add the target functions to the CLASSTYPE_METHOD_VEC if
6584 an enclosing scope is a template class, so that this function be
6585 found by lookup_fnfields_1 when the using declaration is not
6586 instantiated yet. */
6587 for (x = TYPE_FIELDS (t); x; x = DECL_CHAIN (x))
6588 if (TREE_CODE (x) == USING_DECL)
6589 {
6590 tree fn = strip_using_decl (x);
6591 if (is_overloaded_fn (fn))
6592 for (; fn; fn = OVL_NEXT (fn))
6593 add_method (t, OVL_CURRENT (fn), x);
6594 }
6595
6596 /* Remember current #pragma pack value. */
6597 TYPE_PRECISION (t) = maximum_field_alignment;
6598
6599 /* Fix up any variants we've already built. */
6600 for (x = TYPE_NEXT_VARIANT (t); x; x = TYPE_NEXT_VARIANT (x))
6601 {
6602 TYPE_SIZE (x) = TYPE_SIZE (t);
6603 TYPE_SIZE_UNIT (x) = TYPE_SIZE_UNIT (t);
6604 TYPE_FIELDS (x) = TYPE_FIELDS (t);
6605 TYPE_METHODS (x) = TYPE_METHODS (t);
6606 }
6607 }
6608 else
6609 finish_struct_1 (t);
6610
6611 input_location = saved_loc;
6612
6613 TYPE_BEING_DEFINED (t) = 0;
6614
6615 if (current_class_type)
6616 popclass ();
6617 else
6618 error ("trying to finish struct, but kicked out due to previous parse errors");
6619
6620 if (processing_template_decl && at_function_scope_p ()
6621 /* Lambdas are defined by the LAMBDA_EXPR. */
6622 && !LAMBDA_TYPE_P (t))
6623 add_stmt (build_min (TAG_DEFN, t));
6624
6625 return t;
6626 }
6627
6628 /* Hash table to avoid endless recursion when handling references. */
6629 static hash_table <pointer_hash <tree_node> > fixed_type_or_null_ref_ht;
6630
6631 /* Return the dynamic type of INSTANCE, if known.
6632 Used to determine whether the virtual function table is needed
6633 or not.
6634
6635 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6636 of our knowledge of its type. *NONNULL should be initialized
6637 before this function is called. */
6638
6639 static tree
fixed_type_or_null(tree instance,int * nonnull,int * cdtorp)6640 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp)
6641 {
6642 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
6643
6644 switch (TREE_CODE (instance))
6645 {
6646 case INDIRECT_REF:
6647 if (POINTER_TYPE_P (TREE_TYPE (instance)))
6648 return NULL_TREE;
6649 else
6650 return RECUR (TREE_OPERAND (instance, 0));
6651
6652 case CALL_EXPR:
6653 /* This is a call to a constructor, hence it's never zero. */
6654 if (TREE_HAS_CONSTRUCTOR (instance))
6655 {
6656 if (nonnull)
6657 *nonnull = 1;
6658 return TREE_TYPE (instance);
6659 }
6660 return NULL_TREE;
6661
6662 case SAVE_EXPR:
6663 /* This is a call to a constructor, hence it's never zero. */
6664 if (TREE_HAS_CONSTRUCTOR (instance))
6665 {
6666 if (nonnull)
6667 *nonnull = 1;
6668 return TREE_TYPE (instance);
6669 }
6670 return RECUR (TREE_OPERAND (instance, 0));
6671
6672 case POINTER_PLUS_EXPR:
6673 case PLUS_EXPR:
6674 case MINUS_EXPR:
6675 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
6676 return RECUR (TREE_OPERAND (instance, 0));
6677 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
6678 /* Propagate nonnull. */
6679 return RECUR (TREE_OPERAND (instance, 0));
6680
6681 return NULL_TREE;
6682
6683 CASE_CONVERT:
6684 return RECUR (TREE_OPERAND (instance, 0));
6685
6686 case ADDR_EXPR:
6687 instance = TREE_OPERAND (instance, 0);
6688 if (nonnull)
6689 {
6690 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
6691 with a real object -- given &p->f, p can still be null. */
6692 tree t = get_base_address (instance);
6693 /* ??? Probably should check DECL_WEAK here. */
6694 if (t && DECL_P (t))
6695 *nonnull = 1;
6696 }
6697 return RECUR (instance);
6698
6699 case COMPONENT_REF:
6700 /* If this component is really a base class reference, then the field
6701 itself isn't definitive. */
6702 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
6703 return RECUR (TREE_OPERAND (instance, 0));
6704 return RECUR (TREE_OPERAND (instance, 1));
6705
6706 case VAR_DECL:
6707 case FIELD_DECL:
6708 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
6709 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
6710 {
6711 if (nonnull)
6712 *nonnull = 1;
6713 return TREE_TYPE (TREE_TYPE (instance));
6714 }
6715 /* fall through... */
6716 case TARGET_EXPR:
6717 case PARM_DECL:
6718 case RESULT_DECL:
6719 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance)))
6720 {
6721 if (nonnull)
6722 *nonnull = 1;
6723 return TREE_TYPE (instance);
6724 }
6725 else if (instance == current_class_ptr)
6726 {
6727 if (nonnull)
6728 *nonnull = 1;
6729
6730 /* if we're in a ctor or dtor, we know our type. If
6731 current_class_ptr is set but we aren't in a function, we're in
6732 an NSDMI (and therefore a constructor). */
6733 if (current_scope () != current_function_decl
6734 || (DECL_LANG_SPECIFIC (current_function_decl)
6735 && (DECL_CONSTRUCTOR_P (current_function_decl)
6736 || DECL_DESTRUCTOR_P (current_function_decl))))
6737 {
6738 if (cdtorp)
6739 *cdtorp = 1;
6740 return TREE_TYPE (TREE_TYPE (instance));
6741 }
6742 }
6743 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
6744 {
6745 /* We only need one hash table because it is always left empty. */
6746 if (!fixed_type_or_null_ref_ht.is_created ())
6747 fixed_type_or_null_ref_ht.create (37);
6748
6749 /* Reference variables should be references to objects. */
6750 if (nonnull)
6751 *nonnull = 1;
6752
6753 /* Enter the INSTANCE in a table to prevent recursion; a
6754 variable's initializer may refer to the variable
6755 itself. */
6756 if (TREE_CODE (instance) == VAR_DECL
6757 && DECL_INITIAL (instance)
6758 && !type_dependent_expression_p_push (DECL_INITIAL (instance))
6759 && !fixed_type_or_null_ref_ht.find (instance))
6760 {
6761 tree type;
6762 tree_node **slot;
6763
6764 slot = fixed_type_or_null_ref_ht.find_slot (instance, INSERT);
6765 *slot = instance;
6766 type = RECUR (DECL_INITIAL (instance));
6767 fixed_type_or_null_ref_ht.remove_elt (instance);
6768
6769 return type;
6770 }
6771 }
6772 return NULL_TREE;
6773
6774 default:
6775 return NULL_TREE;
6776 }
6777 #undef RECUR
6778 }
6779
6780 /* Return nonzero if the dynamic type of INSTANCE is known, and
6781 equivalent to the static type. We also handle the case where
6782 INSTANCE is really a pointer. Return negative if this is a
6783 ctor/dtor. There the dynamic type is known, but this might not be
6784 the most derived base of the original object, and hence virtual
6785 bases may not be layed out according to this type.
6786
6787 Used to determine whether the virtual function table is needed
6788 or not.
6789
6790 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
6791 of our knowledge of its type. *NONNULL should be initialized
6792 before this function is called. */
6793
6794 int
resolves_to_fixed_type_p(tree instance,int * nonnull)6795 resolves_to_fixed_type_p (tree instance, int* nonnull)
6796 {
6797 tree t = TREE_TYPE (instance);
6798 int cdtorp = 0;
6799 tree fixed;
6800
6801 /* processing_template_decl can be false in a template if we're in
6802 fold_non_dependent_expr, but we still want to suppress this check. */
6803 if (in_template_function ())
6804 {
6805 /* In a template we only care about the type of the result. */
6806 if (nonnull)
6807 *nonnull = true;
6808 return true;
6809 }
6810
6811 fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
6812 if (fixed == NULL_TREE)
6813 return 0;
6814 if (POINTER_TYPE_P (t))
6815 t = TREE_TYPE (t);
6816 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
6817 return 0;
6818 return cdtorp ? -1 : 1;
6819 }
6820
6821
6822 void
init_class_processing(void)6823 init_class_processing (void)
6824 {
6825 current_class_depth = 0;
6826 current_class_stack_size = 10;
6827 current_class_stack
6828 = XNEWVEC (struct class_stack_node, current_class_stack_size);
6829 vec_alloc (local_classes, 8);
6830 sizeof_biggest_empty_class = size_zero_node;
6831
6832 ridpointers[(int) RID_PUBLIC] = access_public_node;
6833 ridpointers[(int) RID_PRIVATE] = access_private_node;
6834 ridpointers[(int) RID_PROTECTED] = access_protected_node;
6835 }
6836
6837 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
6838
6839 static void
restore_class_cache(void)6840 restore_class_cache (void)
6841 {
6842 tree type;
6843
6844 /* We are re-entering the same class we just left, so we don't
6845 have to search the whole inheritance matrix to find all the
6846 decls to bind again. Instead, we install the cached
6847 class_shadowed list and walk through it binding names. */
6848 push_binding_level (previous_class_level);
6849 class_binding_level = previous_class_level;
6850 /* Restore IDENTIFIER_TYPE_VALUE. */
6851 for (type = class_binding_level->type_shadowed;
6852 type;
6853 type = TREE_CHAIN (type))
6854 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
6855 }
6856
6857 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
6858 appropriate for TYPE.
6859
6860 So that we may avoid calls to lookup_name, we cache the _TYPE
6861 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
6862
6863 For multiple inheritance, we perform a two-pass depth-first search
6864 of the type lattice. */
6865
6866 void
pushclass(tree type)6867 pushclass (tree type)
6868 {
6869 class_stack_node_t csn;
6870
6871 type = TYPE_MAIN_VARIANT (type);
6872
6873 /* Make sure there is enough room for the new entry on the stack. */
6874 if (current_class_depth + 1 >= current_class_stack_size)
6875 {
6876 current_class_stack_size *= 2;
6877 current_class_stack
6878 = XRESIZEVEC (struct class_stack_node, current_class_stack,
6879 current_class_stack_size);
6880 }
6881
6882 /* Insert a new entry on the class stack. */
6883 csn = current_class_stack + current_class_depth;
6884 csn->name = current_class_name;
6885 csn->type = current_class_type;
6886 csn->access = current_access_specifier;
6887 csn->names_used = 0;
6888 csn->hidden = 0;
6889 current_class_depth++;
6890
6891 /* Now set up the new type. */
6892 current_class_name = TYPE_NAME (type);
6893 if (TREE_CODE (current_class_name) == TYPE_DECL)
6894 current_class_name = DECL_NAME (current_class_name);
6895 current_class_type = type;
6896
6897 /* By default, things in classes are private, while things in
6898 structures or unions are public. */
6899 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
6900 ? access_private_node
6901 : access_public_node);
6902
6903 if (previous_class_level
6904 && type != previous_class_level->this_entity
6905 && current_class_depth == 1)
6906 {
6907 /* Forcibly remove any old class remnants. */
6908 invalidate_class_lookup_cache ();
6909 }
6910
6911 if (!previous_class_level
6912 || type != previous_class_level->this_entity
6913 || current_class_depth > 1)
6914 pushlevel_class ();
6915 else
6916 restore_class_cache ();
6917 }
6918
6919 /* When we exit a toplevel class scope, we save its binding level so
6920 that we can restore it quickly. Here, we've entered some other
6921 class, so we must invalidate our cache. */
6922
6923 void
invalidate_class_lookup_cache(void)6924 invalidate_class_lookup_cache (void)
6925 {
6926 previous_class_level = NULL;
6927 }
6928
6929 /* Get out of the current class scope. If we were in a class scope
6930 previously, that is the one popped to. */
6931
6932 void
popclass(void)6933 popclass (void)
6934 {
6935 poplevel_class ();
6936
6937 current_class_depth--;
6938 current_class_name = current_class_stack[current_class_depth].name;
6939 current_class_type = current_class_stack[current_class_depth].type;
6940 current_access_specifier = current_class_stack[current_class_depth].access;
6941 if (current_class_stack[current_class_depth].names_used)
6942 splay_tree_delete (current_class_stack[current_class_depth].names_used);
6943 }
6944
6945 /* Mark the top of the class stack as hidden. */
6946
6947 void
push_class_stack(void)6948 push_class_stack (void)
6949 {
6950 if (current_class_depth)
6951 ++current_class_stack[current_class_depth - 1].hidden;
6952 }
6953
6954 /* Mark the top of the class stack as un-hidden. */
6955
6956 void
pop_class_stack(void)6957 pop_class_stack (void)
6958 {
6959 if (current_class_depth)
6960 --current_class_stack[current_class_depth - 1].hidden;
6961 }
6962
6963 /* Returns 1 if the class type currently being defined is either T or
6964 a nested type of T. */
6965
6966 bool
currently_open_class(tree t)6967 currently_open_class (tree t)
6968 {
6969 int i;
6970
6971 if (!CLASS_TYPE_P (t))
6972 return false;
6973
6974 t = TYPE_MAIN_VARIANT (t);
6975
6976 /* We start looking from 1 because entry 0 is from global scope,
6977 and has no type. */
6978 for (i = current_class_depth; i > 0; --i)
6979 {
6980 tree c;
6981 if (i == current_class_depth)
6982 c = current_class_type;
6983 else
6984 {
6985 if (current_class_stack[i].hidden)
6986 break;
6987 c = current_class_stack[i].type;
6988 }
6989 if (!c)
6990 continue;
6991 if (same_type_p (c, t))
6992 return true;
6993 }
6994 return false;
6995 }
6996
6997 /* If either current_class_type or one of its enclosing classes are derived
6998 from T, return the appropriate type. Used to determine how we found
6999 something via unqualified lookup. */
7000
7001 tree
currently_open_derived_class(tree t)7002 currently_open_derived_class (tree t)
7003 {
7004 int i;
7005
7006 /* The bases of a dependent type are unknown. */
7007 if (dependent_type_p (t))
7008 return NULL_TREE;
7009
7010 if (!current_class_type)
7011 return NULL_TREE;
7012
7013 if (DERIVED_FROM_P (t, current_class_type))
7014 return current_class_type;
7015
7016 for (i = current_class_depth - 1; i > 0; --i)
7017 {
7018 if (current_class_stack[i].hidden)
7019 break;
7020 if (DERIVED_FROM_P (t, current_class_stack[i].type))
7021 return current_class_stack[i].type;
7022 }
7023
7024 return NULL_TREE;
7025 }
7026
7027 /* Returns the innermost class type which is not a lambda closure type. */
7028
7029 tree
current_nonlambda_class_type(void)7030 current_nonlambda_class_type (void)
7031 {
7032 int i;
7033
7034 /* We start looking from 1 because entry 0 is from global scope,
7035 and has no type. */
7036 for (i = current_class_depth; i > 0; --i)
7037 {
7038 tree c;
7039 if (i == current_class_depth)
7040 c = current_class_type;
7041 else
7042 {
7043 if (current_class_stack[i].hidden)
7044 break;
7045 c = current_class_stack[i].type;
7046 }
7047 if (!c)
7048 continue;
7049 if (!LAMBDA_TYPE_P (c))
7050 return c;
7051 }
7052 return NULL_TREE;
7053 }
7054
7055 /* When entering a class scope, all enclosing class scopes' names with
7056 static meaning (static variables, static functions, types and
7057 enumerators) have to be visible. This recursive function calls
7058 pushclass for all enclosing class contexts until global or a local
7059 scope is reached. TYPE is the enclosed class. */
7060
7061 void
push_nested_class(tree type)7062 push_nested_class (tree type)
7063 {
7064 /* A namespace might be passed in error cases, like A::B:C. */
7065 if (type == NULL_TREE
7066 || !CLASS_TYPE_P (type))
7067 return;
7068
7069 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type)));
7070
7071 pushclass (type);
7072 }
7073
7074 /* Undoes a push_nested_class call. */
7075
7076 void
pop_nested_class(void)7077 pop_nested_class (void)
7078 {
7079 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
7080
7081 popclass ();
7082 if (context && CLASS_TYPE_P (context))
7083 pop_nested_class ();
7084 }
7085
7086 /* Returns the number of extern "LANG" blocks we are nested within. */
7087
7088 int
current_lang_depth(void)7089 current_lang_depth (void)
7090 {
7091 return vec_safe_length (current_lang_base);
7092 }
7093
7094 /* Set global variables CURRENT_LANG_NAME to appropriate value
7095 so that behavior of name-mangling machinery is correct. */
7096
7097 void
push_lang_context(tree name)7098 push_lang_context (tree name)
7099 {
7100 vec_safe_push (current_lang_base, current_lang_name);
7101
7102 if (name == lang_name_cplusplus)
7103 {
7104 current_lang_name = name;
7105 }
7106 else if (name == lang_name_java)
7107 {
7108 current_lang_name = name;
7109 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
7110 (See record_builtin_java_type in decl.c.) However, that causes
7111 incorrect debug entries if these types are actually used.
7112 So we re-enable debug output after extern "Java". */
7113 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
7114 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
7115 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
7116 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
7117 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
7118 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
7119 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
7120 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
7121 }
7122 else if (name == lang_name_c)
7123 {
7124 current_lang_name = name;
7125 }
7126 else
7127 error ("language string %<\"%E\"%> not recognized", name);
7128 }
7129
7130 /* Get out of the current language scope. */
7131
7132 void
pop_lang_context(void)7133 pop_lang_context (void)
7134 {
7135 current_lang_name = current_lang_base->pop ();
7136 }
7137
7138 /* Type instantiation routines. */
7139
7140 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
7141 matches the TARGET_TYPE. If there is no satisfactory match, return
7142 error_mark_node, and issue an error & warning messages under
7143 control of FLAGS. Permit pointers to member function if FLAGS
7144 permits. If TEMPLATE_ONLY, the name of the overloaded function was
7145 a template-id, and EXPLICIT_TARGS are the explicitly provided
7146 template arguments.
7147
7148 If OVERLOAD is for one or more member functions, then ACCESS_PATH
7149 is the base path used to reference those member functions. If
7150 the address is resolved to a member function, access checks will be
7151 performed and errors issued if appropriate. */
7152
7153 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)7154 resolve_address_of_overloaded_function (tree target_type,
7155 tree overload,
7156 tsubst_flags_t flags,
7157 bool template_only,
7158 tree explicit_targs,
7159 tree access_path)
7160 {
7161 /* Here's what the standard says:
7162
7163 [over.over]
7164
7165 If the name is a function template, template argument deduction
7166 is done, and if the argument deduction succeeds, the deduced
7167 arguments are used to generate a single template function, which
7168 is added to the set of overloaded functions considered.
7169
7170 Non-member functions and static member functions match targets of
7171 type "pointer-to-function" or "reference-to-function." Nonstatic
7172 member functions match targets of type "pointer-to-member
7173 function;" the function type of the pointer to member is used to
7174 select the member function from the set of overloaded member
7175 functions. If a nonstatic member function is selected, the
7176 reference to the overloaded function name is required to have the
7177 form of a pointer to member as described in 5.3.1.
7178
7179 If more than one function is selected, any template functions in
7180 the set are eliminated if the set also contains a non-template
7181 function, and any given template function is eliminated if the
7182 set contains a second template function that is more specialized
7183 than the first according to the partial ordering rules 14.5.5.2.
7184 After such eliminations, if any, there shall remain exactly one
7185 selected function. */
7186
7187 int is_ptrmem = 0;
7188 /* We store the matches in a TREE_LIST rooted here. The functions
7189 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
7190 interoperability with most_specialized_instantiation. */
7191 tree matches = NULL_TREE;
7192 tree fn;
7193 tree target_fn_type;
7194
7195 /* By the time we get here, we should be seeing only real
7196 pointer-to-member types, not the internal POINTER_TYPE to
7197 METHOD_TYPE representation. */
7198 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
7199 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
7200
7201 gcc_assert (is_overloaded_fn (overload));
7202
7203 /* Check that the TARGET_TYPE is reasonable. */
7204 if (TYPE_PTRFN_P (target_type))
7205 /* This is OK. */;
7206 else if (TYPE_PTRMEMFUNC_P (target_type))
7207 /* This is OK, too. */
7208 is_ptrmem = 1;
7209 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
7210 /* This is OK, too. This comes from a conversion to reference
7211 type. */
7212 target_type = build_reference_type (target_type);
7213 else
7214 {
7215 if (flags & tf_error)
7216 error ("cannot resolve overloaded function %qD based on"
7217 " conversion to type %qT",
7218 DECL_NAME (OVL_FUNCTION (overload)), target_type);
7219 return error_mark_node;
7220 }
7221
7222 /* Non-member functions and static member functions match targets of type
7223 "pointer-to-function" or "reference-to-function." Nonstatic member
7224 functions match targets of type "pointer-to-member-function;" the
7225 function type of the pointer to member is used to select the member
7226 function from the set of overloaded member functions.
7227
7228 So figure out the FUNCTION_TYPE that we want to match against. */
7229 target_fn_type = static_fn_type (target_type);
7230
7231 /* If we can find a non-template function that matches, we can just
7232 use it. There's no point in generating template instantiations
7233 if we're just going to throw them out anyhow. But, of course, we
7234 can only do this when we don't *need* a template function. */
7235 if (!template_only)
7236 {
7237 tree fns;
7238
7239 for (fns = overload; fns; fns = OVL_NEXT (fns))
7240 {
7241 tree fn = OVL_CURRENT (fns);
7242
7243 if (TREE_CODE (fn) == TEMPLATE_DECL)
7244 /* We're not looking for templates just yet. */
7245 continue;
7246
7247 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
7248 != is_ptrmem)
7249 /* We're looking for a non-static member, and this isn't
7250 one, or vice versa. */
7251 continue;
7252
7253 /* Ignore functions which haven't been explicitly
7254 declared. */
7255 if (DECL_ANTICIPATED (fn))
7256 continue;
7257
7258 /* See if there's a match. */
7259 if (same_type_p (target_fn_type, static_fn_type (fn)))
7260 matches = tree_cons (fn, NULL_TREE, matches);
7261 }
7262 }
7263
7264 /* Now, if we've already got a match (or matches), there's no need
7265 to proceed to the template functions. But, if we don't have a
7266 match we need to look at them, too. */
7267 if (!matches)
7268 {
7269 tree target_arg_types;
7270 tree target_ret_type;
7271 tree fns;
7272 tree *args;
7273 unsigned int nargs, ia;
7274 tree arg;
7275
7276 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
7277 target_ret_type = TREE_TYPE (target_fn_type);
7278
7279 nargs = list_length (target_arg_types);
7280 args = XALLOCAVEC (tree, nargs);
7281 for (arg = target_arg_types, ia = 0;
7282 arg != NULL_TREE && arg != void_list_node;
7283 arg = TREE_CHAIN (arg), ++ia)
7284 args[ia] = TREE_VALUE (arg);
7285 nargs = ia;
7286
7287 for (fns = overload; fns; fns = OVL_NEXT (fns))
7288 {
7289 tree fn = OVL_CURRENT (fns);
7290 tree instantiation;
7291 tree targs;
7292
7293 if (TREE_CODE (fn) != TEMPLATE_DECL)
7294 /* We're only looking for templates. */
7295 continue;
7296
7297 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
7298 != is_ptrmem)
7299 /* We're not looking for a non-static member, and this is
7300 one, or vice versa. */
7301 continue;
7302
7303 /* Try to do argument deduction. */
7304 targs = make_tree_vec (DECL_NTPARMS (fn));
7305 instantiation = fn_type_unification (fn, explicit_targs, targs, args,
7306 nargs, target_ret_type,
7307 DEDUCE_EXACT, LOOKUP_NORMAL,
7308 false);
7309 if (instantiation == error_mark_node)
7310 /* Instantiation failed. */
7311 continue;
7312
7313 /* See if there's a match. */
7314 if (same_type_p (target_fn_type, static_fn_type (instantiation)))
7315 matches = tree_cons (instantiation, fn, matches);
7316 }
7317
7318 /* Now, remove all but the most specialized of the matches. */
7319 if (matches)
7320 {
7321 tree match = most_specialized_instantiation (matches);
7322
7323 if (match != error_mark_node)
7324 matches = tree_cons (TREE_PURPOSE (match),
7325 NULL_TREE,
7326 NULL_TREE);
7327 }
7328 }
7329
7330 /* Now we should have exactly one function in MATCHES. */
7331 if (matches == NULL_TREE)
7332 {
7333 /* There were *no* matches. */
7334 if (flags & tf_error)
7335 {
7336 error ("no matches converting function %qD to type %q#T",
7337 DECL_NAME (OVL_CURRENT (overload)),
7338 target_type);
7339
7340 print_candidates (overload);
7341 }
7342 return error_mark_node;
7343 }
7344 else if (TREE_CHAIN (matches))
7345 {
7346 /* There were too many matches. First check if they're all
7347 the same function. */
7348 tree match = NULL_TREE;
7349
7350 fn = TREE_PURPOSE (matches);
7351
7352 /* For multi-versioned functions, more than one match is just fine and
7353 decls_match will return false as they are different. */
7354 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match))
7355 if (!decls_match (fn, TREE_PURPOSE (match))
7356 && !targetm.target_option.function_versions
7357 (fn, TREE_PURPOSE (match)))
7358 break;
7359
7360 if (match)
7361 {
7362 if (flags & tf_error)
7363 {
7364 error ("converting overloaded function %qD to type %q#T is ambiguous",
7365 DECL_NAME (OVL_FUNCTION (overload)),
7366 target_type);
7367
7368 /* Since print_candidates expects the functions in the
7369 TREE_VALUE slot, we flip them here. */
7370 for (match = matches; match; match = TREE_CHAIN (match))
7371 TREE_VALUE (match) = TREE_PURPOSE (match);
7372
7373 print_candidates (matches);
7374 }
7375
7376 return error_mark_node;
7377 }
7378 }
7379
7380 /* Good, exactly one match. Now, convert it to the correct type. */
7381 fn = TREE_PURPOSE (matches);
7382
7383 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
7384 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
7385 {
7386 static int explained;
7387
7388 if (!(flags & tf_error))
7389 return error_mark_node;
7390
7391 permerror (input_location, "assuming pointer to member %qD", fn);
7392 if (!explained)
7393 {
7394 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn);
7395 explained = 1;
7396 }
7397 }
7398
7399 /* If a pointer to a function that is multi-versioned is requested, the
7400 pointer to the dispatcher function is returned instead. This works
7401 well because indirectly calling the function will dispatch the right
7402 function version at run-time. */
7403 if (DECL_FUNCTION_VERSIONED (fn))
7404 {
7405 fn = get_function_version_dispatcher (fn);
7406 if (fn == NULL)
7407 return error_mark_node;
7408 /* Mark all the versions corresponding to the dispatcher as used. */
7409 if (!(flags & tf_conv))
7410 mark_versions_used (fn);
7411 }
7412
7413 /* If we're doing overload resolution purely for the purpose of
7414 determining conversion sequences, we should not consider the
7415 function used. If this conversion sequence is selected, the
7416 function will be marked as used at this point. */
7417 if (!(flags & tf_conv))
7418 {
7419 /* Make =delete work with SFINAE. */
7420 if (DECL_DELETED_FN (fn) && !(flags & tf_error))
7421 return error_mark_node;
7422
7423 mark_used (fn);
7424 }
7425
7426 /* We could not check access to member functions when this
7427 expression was originally created since we did not know at that
7428 time to which function the expression referred. */
7429 if (DECL_FUNCTION_MEMBER_P (fn))
7430 {
7431 gcc_assert (access_path);
7432 perform_or_defer_access_check (access_path, fn, fn, flags);
7433 }
7434
7435 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
7436 return cp_build_addr_expr (fn, flags);
7437 else
7438 {
7439 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
7440 will mark the function as addressed, but here we must do it
7441 explicitly. */
7442 cxx_mark_addressable (fn);
7443
7444 return fn;
7445 }
7446 }
7447
7448 /* This function will instantiate the type of the expression given in
7449 RHS to match the type of LHSTYPE. If errors exist, then return
7450 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
7451 we complain on errors. If we are not complaining, never modify rhs,
7452 as overload resolution wants to try many possible instantiations, in
7453 the hope that at least one will work.
7454
7455 For non-recursive calls, LHSTYPE should be a function, pointer to
7456 function, or a pointer to member function. */
7457
7458 tree
instantiate_type(tree lhstype,tree rhs,tsubst_flags_t flags)7459 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
7460 {
7461 tsubst_flags_t flags_in = flags;
7462 tree access_path = NULL_TREE;
7463
7464 flags &= ~tf_ptrmem_ok;
7465
7466 if (lhstype == unknown_type_node)
7467 {
7468 if (flags & tf_error)
7469 error ("not enough type information");
7470 return error_mark_node;
7471 }
7472
7473 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
7474 {
7475 if (same_type_p (lhstype, TREE_TYPE (rhs)))
7476 return rhs;
7477 if (flag_ms_extensions
7478 && TYPE_PTRMEMFUNC_P (lhstype)
7479 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
7480 /* Microsoft allows `A::f' to be resolved to a
7481 pointer-to-member. */
7482 ;
7483 else
7484 {
7485 if (flags & tf_error)
7486 error ("cannot convert %qE from type %qT to type %qT",
7487 rhs, TREE_TYPE (rhs), lhstype);
7488 return error_mark_node;
7489 }
7490 }
7491
7492 if (BASELINK_P (rhs))
7493 {
7494 access_path = BASELINK_ACCESS_BINFO (rhs);
7495 rhs = BASELINK_FUNCTIONS (rhs);
7496 }
7497
7498 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
7499 deduce any type information. */
7500 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
7501 {
7502 if (flags & tf_error)
7503 error ("not enough type information");
7504 return error_mark_node;
7505 }
7506
7507 /* There only a few kinds of expressions that may have a type
7508 dependent on overload resolution. */
7509 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
7510 || TREE_CODE (rhs) == COMPONENT_REF
7511 || is_overloaded_fn (rhs)
7512 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL));
7513
7514 /* This should really only be used when attempting to distinguish
7515 what sort of a pointer to function we have. For now, any
7516 arithmetic operation which is not supported on pointers
7517 is rejected as an error. */
7518
7519 switch (TREE_CODE (rhs))
7520 {
7521 case COMPONENT_REF:
7522 {
7523 tree member = TREE_OPERAND (rhs, 1);
7524
7525 member = instantiate_type (lhstype, member, flags);
7526 if (member != error_mark_node
7527 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
7528 /* Do not lose object's side effects. */
7529 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
7530 TREE_OPERAND (rhs, 0), member);
7531 return member;
7532 }
7533
7534 case OFFSET_REF:
7535 rhs = TREE_OPERAND (rhs, 1);
7536 if (BASELINK_P (rhs))
7537 return instantiate_type (lhstype, rhs, flags_in);
7538
7539 /* This can happen if we are forming a pointer-to-member for a
7540 member template. */
7541 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
7542
7543 /* Fall through. */
7544
7545 case TEMPLATE_ID_EXPR:
7546 {
7547 tree fns = TREE_OPERAND (rhs, 0);
7548 tree args = TREE_OPERAND (rhs, 1);
7549
7550 return
7551 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
7552 /*template_only=*/true,
7553 args, access_path);
7554 }
7555
7556 case OVERLOAD:
7557 case FUNCTION_DECL:
7558 return
7559 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
7560 /*template_only=*/false,
7561 /*explicit_targs=*/NULL_TREE,
7562 access_path);
7563
7564 case ADDR_EXPR:
7565 {
7566 if (PTRMEM_OK_P (rhs))
7567 flags |= tf_ptrmem_ok;
7568
7569 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
7570 }
7571
7572 case ERROR_MARK:
7573 return error_mark_node;
7574
7575 default:
7576 gcc_unreachable ();
7577 }
7578 return error_mark_node;
7579 }
7580
7581 /* Return the name of the virtual function pointer field
7582 (as an IDENTIFIER_NODE) for the given TYPE. Note that
7583 this may have to look back through base types to find the
7584 ultimate field name. (For single inheritance, these could
7585 all be the same name. Who knows for multiple inheritance). */
7586
7587 static tree
get_vfield_name(tree type)7588 get_vfield_name (tree type)
7589 {
7590 tree binfo, base_binfo;
7591 char *buf;
7592
7593 for (binfo = TYPE_BINFO (type);
7594 BINFO_N_BASE_BINFOS (binfo);
7595 binfo = base_binfo)
7596 {
7597 base_binfo = BINFO_BASE_BINFO (binfo, 0);
7598
7599 if (BINFO_VIRTUAL_P (base_binfo)
7600 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
7601 break;
7602 }
7603
7604 type = BINFO_TYPE (binfo);
7605 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
7606 + TYPE_NAME_LENGTH (type) + 2);
7607 sprintf (buf, VFIELD_NAME_FORMAT,
7608 IDENTIFIER_POINTER (constructor_name (type)));
7609 return get_identifier (buf);
7610 }
7611
7612 void
print_class_statistics(void)7613 print_class_statistics (void)
7614 {
7615 if (! GATHER_STATISTICS)
7616 return;
7617
7618 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
7619 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
7620 if (n_vtables)
7621 {
7622 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
7623 n_vtables, n_vtable_searches);
7624 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
7625 n_vtable_entries, n_vtable_elems);
7626 }
7627 }
7628
7629 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
7630 according to [class]:
7631 The class-name is also inserted
7632 into the scope of the class itself. For purposes of access checking,
7633 the inserted class name is treated as if it were a public member name. */
7634
7635 void
build_self_reference(void)7636 build_self_reference (void)
7637 {
7638 tree name = constructor_name (current_class_type);
7639 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
7640 tree saved_cas;
7641
7642 DECL_NONLOCAL (value) = 1;
7643 DECL_CONTEXT (value) = current_class_type;
7644 DECL_ARTIFICIAL (value) = 1;
7645 SET_DECL_SELF_REFERENCE_P (value);
7646 set_underlying_type (value);
7647
7648 if (processing_template_decl)
7649 value = push_template_decl (value);
7650
7651 saved_cas = current_access_specifier;
7652 current_access_specifier = access_public_node;
7653 finish_member_declaration (value);
7654 current_access_specifier = saved_cas;
7655 }
7656
7657 /* Returns 1 if TYPE contains only padding bytes. */
7658
7659 int
is_empty_class(tree type)7660 is_empty_class (tree type)
7661 {
7662 if (type == error_mark_node)
7663 return 0;
7664
7665 if (! CLASS_TYPE_P (type))
7666 return 0;
7667
7668 /* In G++ 3.2, whether or not a class was empty was determined by
7669 looking at its size. */
7670 if (abi_version_at_least (2))
7671 return CLASSTYPE_EMPTY_P (type);
7672 else
7673 return integer_zerop (CLASSTYPE_SIZE (type));
7674 }
7675
7676 /* Returns true if TYPE contains an empty class. */
7677
7678 static bool
contains_empty_class_p(tree type)7679 contains_empty_class_p (tree type)
7680 {
7681 if (is_empty_class (type))
7682 return true;
7683 if (CLASS_TYPE_P (type))
7684 {
7685 tree field;
7686 tree binfo;
7687 tree base_binfo;
7688 int i;
7689
7690 for (binfo = TYPE_BINFO (type), i = 0;
7691 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7692 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
7693 return true;
7694 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
7695 if (TREE_CODE (field) == FIELD_DECL
7696 && !DECL_ARTIFICIAL (field)
7697 && is_empty_class (TREE_TYPE (field)))
7698 return true;
7699 }
7700 else if (TREE_CODE (type) == ARRAY_TYPE)
7701 return contains_empty_class_p (TREE_TYPE (type));
7702 return false;
7703 }
7704
7705 /* Returns true if TYPE contains no actual data, just various
7706 possible combinations of empty classes and possibly a vptr. */
7707
7708 bool
is_really_empty_class(tree type)7709 is_really_empty_class (tree type)
7710 {
7711 if (CLASS_TYPE_P (type))
7712 {
7713 tree field;
7714 tree binfo;
7715 tree base_binfo;
7716 int i;
7717
7718 /* CLASSTYPE_EMPTY_P isn't set properly until the class is actually laid
7719 out, but we'd like to be able to check this before then. */
7720 if (COMPLETE_TYPE_P (type) && is_empty_class (type))
7721 return true;
7722
7723 for (binfo = TYPE_BINFO (type), i = 0;
7724 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7725 if (!is_really_empty_class (BINFO_TYPE (base_binfo)))
7726 return false;
7727 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
7728 if (TREE_CODE (field) == FIELD_DECL
7729 && !DECL_ARTIFICIAL (field)
7730 && !is_really_empty_class (TREE_TYPE (field)))
7731 return false;
7732 return true;
7733 }
7734 else if (TREE_CODE (type) == ARRAY_TYPE)
7735 return is_really_empty_class (TREE_TYPE (type));
7736 return false;
7737 }
7738
7739 /* Note that NAME was looked up while the current class was being
7740 defined and that the result of that lookup was DECL. */
7741
7742 void
maybe_note_name_used_in_class(tree name,tree decl)7743 maybe_note_name_used_in_class (tree name, tree decl)
7744 {
7745 splay_tree names_used;
7746
7747 /* If we're not defining a class, there's nothing to do. */
7748 if (!(innermost_scope_kind() == sk_class
7749 && TYPE_BEING_DEFINED (current_class_type)
7750 && !LAMBDA_TYPE_P (current_class_type)))
7751 return;
7752
7753 /* If there's already a binding for this NAME, then we don't have
7754 anything to worry about. */
7755 if (lookup_member (current_class_type, name,
7756 /*protect=*/0, /*want_type=*/false, tf_warning_or_error))
7757 return;
7758
7759 if (!current_class_stack[current_class_depth - 1].names_used)
7760 current_class_stack[current_class_depth - 1].names_used
7761 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
7762 names_used = current_class_stack[current_class_depth - 1].names_used;
7763
7764 splay_tree_insert (names_used,
7765 (splay_tree_key) name,
7766 (splay_tree_value) decl);
7767 }
7768
7769 /* Note that NAME was declared (as DECL) in the current class. Check
7770 to see that the declaration is valid. */
7771
7772 void
note_name_declared_in_class(tree name,tree decl)7773 note_name_declared_in_class (tree name, tree decl)
7774 {
7775 splay_tree names_used;
7776 splay_tree_node n;
7777
7778 /* Look to see if we ever used this name. */
7779 names_used
7780 = current_class_stack[current_class_depth - 1].names_used;
7781 if (!names_used)
7782 return;
7783 /* The C language allows members to be declared with a type of the same
7784 name, and the C++ standard says this diagnostic is not required. So
7785 allow it in extern "C" blocks unless predantic is specified.
7786 Allow it in all cases if -ms-extensions is specified. */
7787 if ((!pedantic && current_lang_name == lang_name_c)
7788 || flag_ms_extensions)
7789 return;
7790 n = splay_tree_lookup (names_used, (splay_tree_key) name);
7791 if (n)
7792 {
7793 /* [basic.scope.class]
7794
7795 A name N used in a class S shall refer to the same declaration
7796 in its context and when re-evaluated in the completed scope of
7797 S. */
7798 permerror (input_location, "declaration of %q#D", decl);
7799 permerror (input_location, "changes meaning of %qD from %q+#D",
7800 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
7801 }
7802 }
7803
7804 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
7805 Secondary vtables are merged with primary vtables; this function
7806 will return the VAR_DECL for the primary vtable. */
7807
7808 tree
get_vtbl_decl_for_binfo(tree binfo)7809 get_vtbl_decl_for_binfo (tree binfo)
7810 {
7811 tree decl;
7812
7813 decl = BINFO_VTABLE (binfo);
7814 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR)
7815 {
7816 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
7817 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
7818 }
7819 if (decl)
7820 gcc_assert (TREE_CODE (decl) == VAR_DECL);
7821 return decl;
7822 }
7823
7824
7825 /* Returns the binfo for the primary base of BINFO. If the resulting
7826 BINFO is a virtual base, and it is inherited elsewhere in the
7827 hierarchy, then the returned binfo might not be the primary base of
7828 BINFO in the complete object. Check BINFO_PRIMARY_P or
7829 BINFO_LOST_PRIMARY_P to be sure. */
7830
7831 static tree
get_primary_binfo(tree binfo)7832 get_primary_binfo (tree binfo)
7833 {
7834 tree primary_base;
7835
7836 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
7837 if (!primary_base)
7838 return NULL_TREE;
7839
7840 return copied_binfo (primary_base, binfo);
7841 }
7842
7843 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
7844
7845 static int
maybe_indent_hierarchy(FILE * stream,int indent,int indented_p)7846 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
7847 {
7848 if (!indented_p)
7849 fprintf (stream, "%*s", indent, "");
7850 return 1;
7851 }
7852
7853 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
7854 INDENT should be zero when called from the top level; it is
7855 incremented recursively. IGO indicates the next expected BINFO in
7856 inheritance graph ordering. */
7857
7858 static tree
dump_class_hierarchy_r(FILE * stream,int flags,tree binfo,tree igo,int indent)7859 dump_class_hierarchy_r (FILE *stream,
7860 int flags,
7861 tree binfo,
7862 tree igo,
7863 int indent)
7864 {
7865 int indented = 0;
7866 tree base_binfo;
7867 int i;
7868
7869 indented = maybe_indent_hierarchy (stream, indent, 0);
7870 fprintf (stream, "%s (0x" HOST_WIDE_INT_PRINT_HEX ") ",
7871 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
7872 (HOST_WIDE_INT) (uintptr_t) binfo);
7873 if (binfo != igo)
7874 {
7875 fprintf (stream, "alternative-path\n");
7876 return igo;
7877 }
7878 igo = TREE_CHAIN (binfo);
7879
7880 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
7881 tree_low_cst (BINFO_OFFSET (binfo), 0));
7882 if (is_empty_class (BINFO_TYPE (binfo)))
7883 fprintf (stream, " empty");
7884 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
7885 fprintf (stream, " nearly-empty");
7886 if (BINFO_VIRTUAL_P (binfo))
7887 fprintf (stream, " virtual");
7888 fprintf (stream, "\n");
7889
7890 indented = 0;
7891 if (BINFO_PRIMARY_P (binfo))
7892 {
7893 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7894 fprintf (stream, " primary-for %s (0x" HOST_WIDE_INT_PRINT_HEX ")",
7895 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
7896 TFF_PLAIN_IDENTIFIER),
7897 (HOST_WIDE_INT) (uintptr_t) BINFO_INHERITANCE_CHAIN (binfo));
7898 }
7899 if (BINFO_LOST_PRIMARY_P (binfo))
7900 {
7901 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7902 fprintf (stream, " lost-primary");
7903 }
7904 if (indented)
7905 fprintf (stream, "\n");
7906
7907 if (!(flags & TDF_SLIM))
7908 {
7909 int indented = 0;
7910
7911 if (BINFO_SUBVTT_INDEX (binfo))
7912 {
7913 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7914 fprintf (stream, " subvttidx=%s",
7915 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
7916 TFF_PLAIN_IDENTIFIER));
7917 }
7918 if (BINFO_VPTR_INDEX (binfo))
7919 {
7920 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7921 fprintf (stream, " vptridx=%s",
7922 expr_as_string (BINFO_VPTR_INDEX (binfo),
7923 TFF_PLAIN_IDENTIFIER));
7924 }
7925 if (BINFO_VPTR_FIELD (binfo))
7926 {
7927 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7928 fprintf (stream, " vbaseoffset=%s",
7929 expr_as_string (BINFO_VPTR_FIELD (binfo),
7930 TFF_PLAIN_IDENTIFIER));
7931 }
7932 if (BINFO_VTABLE (binfo))
7933 {
7934 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
7935 fprintf (stream, " vptr=%s",
7936 expr_as_string (BINFO_VTABLE (binfo),
7937 TFF_PLAIN_IDENTIFIER));
7938 }
7939
7940 if (indented)
7941 fprintf (stream, "\n");
7942 }
7943
7944 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
7945 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
7946
7947 return igo;
7948 }
7949
7950 /* Dump the BINFO hierarchy for T. */
7951
7952 static void
dump_class_hierarchy_1(FILE * stream,int flags,tree t)7953 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
7954 {
7955 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
7956 fprintf (stream, " size=%lu align=%lu\n",
7957 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
7958 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
7959 fprintf (stream, " base size=%lu base align=%lu\n",
7960 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
7961 / BITS_PER_UNIT),
7962 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
7963 / BITS_PER_UNIT));
7964 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
7965 fprintf (stream, "\n");
7966 }
7967
7968 /* Debug interface to hierarchy dumping. */
7969
7970 void
debug_class(tree t)7971 debug_class (tree t)
7972 {
7973 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
7974 }
7975
7976 static void
dump_class_hierarchy(tree t)7977 dump_class_hierarchy (tree t)
7978 {
7979 int flags;
7980 FILE *stream = dump_begin (TDI_class, &flags);
7981
7982 if (stream)
7983 {
7984 dump_class_hierarchy_1 (stream, flags, t);
7985 dump_end (TDI_class, stream);
7986 }
7987 }
7988
7989 static void
dump_array(FILE * stream,tree decl)7990 dump_array (FILE * stream, tree decl)
7991 {
7992 tree value;
7993 unsigned HOST_WIDE_INT ix;
7994 HOST_WIDE_INT elt;
7995 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
7996
7997 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
7998 / BITS_PER_UNIT);
7999 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
8000 fprintf (stream, " %s entries",
8001 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
8002 TFF_PLAIN_IDENTIFIER));
8003 fprintf (stream, "\n");
8004
8005 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
8006 ix, value)
8007 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
8008 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
8009 }
8010
8011 static void
dump_vtable(tree t,tree binfo,tree vtable)8012 dump_vtable (tree t, tree binfo, tree vtable)
8013 {
8014 int flags;
8015 FILE *stream = dump_begin (TDI_class, &flags);
8016
8017 if (!stream)
8018 return;
8019
8020 if (!(flags & TDF_SLIM))
8021 {
8022 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
8023
8024 fprintf (stream, "%s for %s",
8025 ctor_vtbl_p ? "Construction vtable" : "Vtable",
8026 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
8027 if (ctor_vtbl_p)
8028 {
8029 if (!BINFO_VIRTUAL_P (binfo))
8030 fprintf (stream, " (0x" HOST_WIDE_INT_PRINT_HEX " instance)",
8031 (HOST_WIDE_INT) (uintptr_t) binfo);
8032 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
8033 }
8034 fprintf (stream, "\n");
8035 dump_array (stream, vtable);
8036 fprintf (stream, "\n");
8037 }
8038
8039 dump_end (TDI_class, stream);
8040 }
8041
8042 static void
dump_vtt(tree t,tree vtt)8043 dump_vtt (tree t, tree vtt)
8044 {
8045 int flags;
8046 FILE *stream = dump_begin (TDI_class, &flags);
8047
8048 if (!stream)
8049 return;
8050
8051 if (!(flags & TDF_SLIM))
8052 {
8053 fprintf (stream, "VTT for %s\n",
8054 type_as_string (t, TFF_PLAIN_IDENTIFIER));
8055 dump_array (stream, vtt);
8056 fprintf (stream, "\n");
8057 }
8058
8059 dump_end (TDI_class, stream);
8060 }
8061
8062 /* Dump a function or thunk and its thunkees. */
8063
8064 static void
dump_thunk(FILE * stream,int indent,tree thunk)8065 dump_thunk (FILE *stream, int indent, tree thunk)
8066 {
8067 static const char spaces[] = " ";
8068 tree name = DECL_NAME (thunk);
8069 tree thunks;
8070
8071 fprintf (stream, "%.*s%p %s %s", indent, spaces,
8072 (void *)thunk,
8073 !DECL_THUNK_P (thunk) ? "function"
8074 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
8075 name ? IDENTIFIER_POINTER (name) : "<unset>");
8076 if (DECL_THUNK_P (thunk))
8077 {
8078 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
8079 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
8080
8081 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
8082 if (!virtual_adjust)
8083 /*NOP*/;
8084 else if (DECL_THIS_THUNK_P (thunk))
8085 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
8086 tree_low_cst (virtual_adjust, 0));
8087 else
8088 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
8089 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
8090 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
8091 if (THUNK_ALIAS (thunk))
8092 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
8093 }
8094 fprintf (stream, "\n");
8095 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
8096 dump_thunk (stream, indent + 2, thunks);
8097 }
8098
8099 /* Dump the thunks for FN. */
8100
8101 void
debug_thunks(tree fn)8102 debug_thunks (tree fn)
8103 {
8104 dump_thunk (stderr, 0, fn);
8105 }
8106
8107 /* Virtual function table initialization. */
8108
8109 /* Create all the necessary vtables for T and its base classes. */
8110
8111 static void
finish_vtbls(tree t)8112 finish_vtbls (tree t)
8113 {
8114 tree vbase;
8115 vec<constructor_elt, va_gc> *v = NULL;
8116 tree vtable = BINFO_VTABLE (TYPE_BINFO (t));
8117
8118 /* We lay out the primary and secondary vtables in one contiguous
8119 vtable. The primary vtable is first, followed by the non-virtual
8120 secondary vtables in inheritance graph order. */
8121 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t), TYPE_BINFO (t),
8122 vtable, t, &v);
8123
8124 /* Then come the virtual bases, also in inheritance graph order. */
8125 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
8126 {
8127 if (!BINFO_VIRTUAL_P (vbase))
8128 continue;
8129 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), vtable, t, &v);
8130 }
8131
8132 if (BINFO_VTABLE (TYPE_BINFO (t)))
8133 initialize_vtable (TYPE_BINFO (t), v);
8134 }
8135
8136 /* Initialize the vtable for BINFO with the INITS. */
8137
8138 static void
initialize_vtable(tree binfo,vec<constructor_elt,va_gc> * inits)8139 initialize_vtable (tree binfo, vec<constructor_elt, va_gc> *inits)
8140 {
8141 tree decl;
8142
8143 layout_vtable_decl (binfo, vec_safe_length (inits));
8144 decl = get_vtbl_decl_for_binfo (binfo);
8145 initialize_artificial_var (decl, inits);
8146 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
8147 }
8148
8149 /* Build the VTT (virtual table table) for T.
8150 A class requires a VTT if it has virtual bases.
8151
8152 This holds
8153 1 - primary virtual pointer for complete object T
8154 2 - secondary VTTs for each direct non-virtual base of T which requires a
8155 VTT
8156 3 - secondary virtual pointers for each direct or indirect base of T which
8157 has virtual bases or is reachable via a virtual path from T.
8158 4 - secondary VTTs for each direct or indirect virtual base of T.
8159
8160 Secondary VTTs look like complete object VTTs without part 4. */
8161
8162 static void
build_vtt(tree t)8163 build_vtt (tree t)
8164 {
8165 tree type;
8166 tree vtt;
8167 tree index;
8168 vec<constructor_elt, va_gc> *inits;
8169
8170 /* Build up the initializers for the VTT. */
8171 inits = NULL;
8172 index = size_zero_node;
8173 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
8174
8175 /* If we didn't need a VTT, we're done. */
8176 if (!inits)
8177 return;
8178
8179 /* Figure out the type of the VTT. */
8180 type = build_array_of_n_type (const_ptr_type_node,
8181 inits->length ());
8182
8183 /* Now, build the VTT object itself. */
8184 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
8185 initialize_artificial_var (vtt, inits);
8186 /* Add the VTT to the vtables list. */
8187 DECL_CHAIN (vtt) = DECL_CHAIN (CLASSTYPE_VTABLES (t));
8188 DECL_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
8189
8190 dump_vtt (t, vtt);
8191 }
8192
8193 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
8194 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
8195 and CHAIN the vtable pointer for this binfo after construction is
8196 complete. VALUE can also be another BINFO, in which case we recurse. */
8197
8198 static tree
binfo_ctor_vtable(tree binfo)8199 binfo_ctor_vtable (tree binfo)
8200 {
8201 tree vt;
8202
8203 while (1)
8204 {
8205 vt = BINFO_VTABLE (binfo);
8206 if (TREE_CODE (vt) == TREE_LIST)
8207 vt = TREE_VALUE (vt);
8208 if (TREE_CODE (vt) == TREE_BINFO)
8209 binfo = vt;
8210 else
8211 break;
8212 }
8213
8214 return vt;
8215 }
8216
8217 /* Data for secondary VTT initialization. */
8218 typedef struct secondary_vptr_vtt_init_data_s
8219 {
8220 /* Is this the primary VTT? */
8221 bool top_level_p;
8222
8223 /* Current index into the VTT. */
8224 tree index;
8225
8226 /* Vector of initializers built up. */
8227 vec<constructor_elt, va_gc> *inits;
8228
8229 /* The type being constructed by this secondary VTT. */
8230 tree type_being_constructed;
8231 } secondary_vptr_vtt_init_data;
8232
8233 /* Recursively build the VTT-initializer for BINFO (which is in the
8234 hierarchy dominated by T). INITS points to the end of the initializer
8235 list to date. INDEX is the VTT index where the next element will be
8236 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
8237 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
8238 for virtual bases of T. When it is not so, we build the constructor
8239 vtables for the BINFO-in-T variant. */
8240
8241 static void
build_vtt_inits(tree binfo,tree t,vec<constructor_elt,va_gc> ** inits,tree * index)8242 build_vtt_inits (tree binfo, tree t, vec<constructor_elt, va_gc> **inits,
8243 tree *index)
8244 {
8245 int i;
8246 tree b;
8247 tree init;
8248 secondary_vptr_vtt_init_data data;
8249 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
8250
8251 /* We only need VTTs for subobjects with virtual bases. */
8252 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
8253 return;
8254
8255 /* We need to use a construction vtable if this is not the primary
8256 VTT. */
8257 if (!top_level_p)
8258 {
8259 build_ctor_vtbl_group (binfo, t);
8260
8261 /* Record the offset in the VTT where this sub-VTT can be found. */
8262 BINFO_SUBVTT_INDEX (binfo) = *index;
8263 }
8264
8265 /* Add the address of the primary vtable for the complete object. */
8266 init = binfo_ctor_vtable (binfo);
8267 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init);
8268 if (top_level_p)
8269 {
8270 gcc_assert (!BINFO_VPTR_INDEX (binfo));
8271 BINFO_VPTR_INDEX (binfo) = *index;
8272 }
8273 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
8274
8275 /* Recursively add the secondary VTTs for non-virtual bases. */
8276 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
8277 if (!BINFO_VIRTUAL_P (b))
8278 build_vtt_inits (b, t, inits, index);
8279
8280 /* Add secondary virtual pointers for all subobjects of BINFO with
8281 either virtual bases or reachable along a virtual path, except
8282 subobjects that are non-virtual primary bases. */
8283 data.top_level_p = top_level_p;
8284 data.index = *index;
8285 data.inits = *inits;
8286 data.type_being_constructed = BINFO_TYPE (binfo);
8287
8288 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
8289
8290 *index = data.index;
8291
8292 /* data.inits might have grown as we added secondary virtual pointers.
8293 Make sure our caller knows about the new vector. */
8294 *inits = data.inits;
8295
8296 if (top_level_p)
8297 /* Add the secondary VTTs for virtual bases in inheritance graph
8298 order. */
8299 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
8300 {
8301 if (!BINFO_VIRTUAL_P (b))
8302 continue;
8303
8304 build_vtt_inits (b, t, inits, index);
8305 }
8306 else
8307 /* Remove the ctor vtables we created. */
8308 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
8309 }
8310
8311 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
8312 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
8313
8314 static tree
dfs_build_secondary_vptr_vtt_inits(tree binfo,void * data_)8315 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
8316 {
8317 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
8318
8319 /* We don't care about bases that don't have vtables. */
8320 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
8321 return dfs_skip_bases;
8322
8323 /* We're only interested in proper subobjects of the type being
8324 constructed. */
8325 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
8326 return NULL_TREE;
8327
8328 /* We're only interested in bases with virtual bases or reachable
8329 via a virtual path from the type being constructed. */
8330 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
8331 || binfo_via_virtual (binfo, data->type_being_constructed)))
8332 return dfs_skip_bases;
8333
8334 /* We're not interested in non-virtual primary bases. */
8335 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
8336 return NULL_TREE;
8337
8338 /* Record the index where this secondary vptr can be found. */
8339 if (data->top_level_p)
8340 {
8341 gcc_assert (!BINFO_VPTR_INDEX (binfo));
8342 BINFO_VPTR_INDEX (binfo) = data->index;
8343
8344 if (BINFO_VIRTUAL_P (binfo))
8345 {
8346 /* It's a primary virtual base, and this is not a
8347 construction vtable. Find the base this is primary of in
8348 the inheritance graph, and use that base's vtable
8349 now. */
8350 while (BINFO_PRIMARY_P (binfo))
8351 binfo = BINFO_INHERITANCE_CHAIN (binfo);
8352 }
8353 }
8354
8355 /* Add the initializer for the secondary vptr itself. */
8356 CONSTRUCTOR_APPEND_ELT (data->inits, NULL_TREE, binfo_ctor_vtable (binfo));
8357
8358 /* Advance the vtt index. */
8359 data->index = size_binop (PLUS_EXPR, data->index,
8360 TYPE_SIZE_UNIT (ptr_type_node));
8361
8362 return NULL_TREE;
8363 }
8364
8365 /* Called from build_vtt_inits via dfs_walk. After building
8366 constructor vtables and generating the sub-vtt from them, we need
8367 to restore the BINFO_VTABLES that were scribbled on. DATA is the
8368 binfo of the base whose sub vtt was generated. */
8369
8370 static tree
dfs_fixup_binfo_vtbls(tree binfo,void * data)8371 dfs_fixup_binfo_vtbls (tree binfo, void* data)
8372 {
8373 tree vtable = BINFO_VTABLE (binfo);
8374
8375 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
8376 /* If this class has no vtable, none of its bases do. */
8377 return dfs_skip_bases;
8378
8379 if (!vtable)
8380 /* This might be a primary base, so have no vtable in this
8381 hierarchy. */
8382 return NULL_TREE;
8383
8384 /* If we scribbled the construction vtable vptr into BINFO, clear it
8385 out now. */
8386 if (TREE_CODE (vtable) == TREE_LIST
8387 && (TREE_PURPOSE (vtable) == (tree) data))
8388 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
8389
8390 return NULL_TREE;
8391 }
8392
8393 /* Build the construction vtable group for BINFO which is in the
8394 hierarchy dominated by T. */
8395
8396 static void
build_ctor_vtbl_group(tree binfo,tree t)8397 build_ctor_vtbl_group (tree binfo, tree t)
8398 {
8399 tree type;
8400 tree vtbl;
8401 tree id;
8402 tree vbase;
8403 vec<constructor_elt, va_gc> *v;
8404
8405 /* See if we've already created this construction vtable group. */
8406 id = mangle_ctor_vtbl_for_type (t, binfo);
8407 if (IDENTIFIER_GLOBAL_VALUE (id))
8408 return;
8409
8410 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
8411 /* Build a version of VTBL (with the wrong type) for use in
8412 constructing the addresses of secondary vtables in the
8413 construction vtable group. */
8414 vtbl = build_vtable (t, id, ptr_type_node);
8415 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
8416 /* Don't export construction vtables from shared libraries. Even on
8417 targets that don't support hidden visibility, this tells
8418 can_refer_decl_in_current_unit_p not to assume that it's safe to
8419 access from a different compilation unit (bz 54314). */
8420 DECL_VISIBILITY (vtbl) = VISIBILITY_HIDDEN;
8421 DECL_VISIBILITY_SPECIFIED (vtbl) = true;
8422
8423 v = NULL;
8424 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
8425 binfo, vtbl, t, &v);
8426
8427 /* Add the vtables for each of our virtual bases using the vbase in T
8428 binfo. */
8429 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
8430 vbase;
8431 vbase = TREE_CHAIN (vbase))
8432 {
8433 tree b;
8434
8435 if (!BINFO_VIRTUAL_P (vbase))
8436 continue;
8437 b = copied_binfo (vbase, binfo);
8438
8439 accumulate_vtbl_inits (b, vbase, binfo, vtbl, t, &v);
8440 }
8441
8442 /* Figure out the type of the construction vtable. */
8443 type = build_array_of_n_type (vtable_entry_type, v->length ());
8444 layout_type (type);
8445 TREE_TYPE (vtbl) = type;
8446 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE;
8447 layout_decl (vtbl, 0);
8448
8449 /* Initialize the construction vtable. */
8450 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
8451 initialize_artificial_var (vtbl, v);
8452 dump_vtable (t, binfo, vtbl);
8453 }
8454
8455 /* Add the vtbl initializers for BINFO (and its bases other than
8456 non-virtual primaries) to the list of INITS. BINFO is in the
8457 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
8458 the constructor the vtbl inits should be accumulated for. (If this
8459 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
8460 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
8461 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
8462 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
8463 but are not necessarily the same in terms of layout. */
8464
8465 static void
accumulate_vtbl_inits(tree binfo,tree orig_binfo,tree rtti_binfo,tree vtbl,tree t,vec<constructor_elt,va_gc> ** inits)8466 accumulate_vtbl_inits (tree binfo,
8467 tree orig_binfo,
8468 tree rtti_binfo,
8469 tree vtbl,
8470 tree t,
8471 vec<constructor_elt, va_gc> **inits)
8472 {
8473 int i;
8474 tree base_binfo;
8475 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
8476
8477 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
8478
8479 /* If it doesn't have a vptr, we don't do anything. */
8480 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
8481 return;
8482
8483 /* If we're building a construction vtable, we're not interested in
8484 subobjects that don't require construction vtables. */
8485 if (ctor_vtbl_p
8486 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
8487 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
8488 return;
8489
8490 /* Build the initializers for the BINFO-in-T vtable. */
8491 dfs_accumulate_vtbl_inits (binfo, orig_binfo, rtti_binfo, vtbl, t, inits);
8492
8493 /* Walk the BINFO and its bases. We walk in preorder so that as we
8494 initialize each vtable we can figure out at what offset the
8495 secondary vtable lies from the primary vtable. We can't use
8496 dfs_walk here because we need to iterate through bases of BINFO
8497 and RTTI_BINFO simultaneously. */
8498 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
8499 {
8500 /* Skip virtual bases. */
8501 if (BINFO_VIRTUAL_P (base_binfo))
8502 continue;
8503 accumulate_vtbl_inits (base_binfo,
8504 BINFO_BASE_BINFO (orig_binfo, i),
8505 rtti_binfo, vtbl, t,
8506 inits);
8507 }
8508 }
8509
8510 /* Called from accumulate_vtbl_inits. Adds the initializers for the
8511 BINFO vtable to L. */
8512
8513 static void
dfs_accumulate_vtbl_inits(tree binfo,tree orig_binfo,tree rtti_binfo,tree orig_vtbl,tree t,vec<constructor_elt,va_gc> ** l)8514 dfs_accumulate_vtbl_inits (tree binfo,
8515 tree orig_binfo,
8516 tree rtti_binfo,
8517 tree orig_vtbl,
8518 tree t,
8519 vec<constructor_elt, va_gc> **l)
8520 {
8521 tree vtbl = NULL_TREE;
8522 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
8523 int n_inits;
8524
8525 if (ctor_vtbl_p
8526 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
8527 {
8528 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
8529 primary virtual base. If it is not the same primary in
8530 the hierarchy of T, we'll need to generate a ctor vtable
8531 for it, to place at its location in T. If it is the same
8532 primary, we still need a VTT entry for the vtable, but it
8533 should point to the ctor vtable for the base it is a
8534 primary for within the sub-hierarchy of RTTI_BINFO.
8535
8536 There are three possible cases:
8537
8538 1) We are in the same place.
8539 2) We are a primary base within a lost primary virtual base of
8540 RTTI_BINFO.
8541 3) We are primary to something not a base of RTTI_BINFO. */
8542
8543 tree b;
8544 tree last = NULL_TREE;
8545
8546 /* First, look through the bases we are primary to for RTTI_BINFO
8547 or a virtual base. */
8548 b = binfo;
8549 while (BINFO_PRIMARY_P (b))
8550 {
8551 b = BINFO_INHERITANCE_CHAIN (b);
8552 last = b;
8553 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
8554 goto found;
8555 }
8556 /* If we run out of primary links, keep looking down our
8557 inheritance chain; we might be an indirect primary. */
8558 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
8559 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
8560 break;
8561 found:
8562
8563 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
8564 base B and it is a base of RTTI_BINFO, this is case 2. In
8565 either case, we share our vtable with LAST, i.e. the
8566 derived-most base within B of which we are a primary. */
8567 if (b == rtti_binfo
8568 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
8569 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
8570 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
8571 binfo_ctor_vtable after everything's been set up. */
8572 vtbl = last;
8573
8574 /* Otherwise, this is case 3 and we get our own. */
8575 }
8576 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
8577 return;
8578
8579 n_inits = vec_safe_length (*l);
8580
8581 if (!vtbl)
8582 {
8583 tree index;
8584 int non_fn_entries;
8585
8586 /* Add the initializer for this vtable. */
8587 build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
8588 &non_fn_entries, l);
8589
8590 /* Figure out the position to which the VPTR should point. */
8591 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, orig_vtbl);
8592 index = size_binop (MULT_EXPR,
8593 TYPE_SIZE_UNIT (vtable_entry_type),
8594 size_int (non_fn_entries + n_inits));
8595 vtbl = fold_build_pointer_plus (vtbl, index);
8596 }
8597
8598 if (ctor_vtbl_p)
8599 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
8600 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
8601 straighten this out. */
8602 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
8603 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
8604 /* Throw away any unneeded intializers. */
8605 (*l)->truncate (n_inits);
8606 else
8607 /* For an ordinary vtable, set BINFO_VTABLE. */
8608 BINFO_VTABLE (binfo) = vtbl;
8609 }
8610
8611 static GTY(()) tree abort_fndecl_addr;
8612
8613 /* Construct the initializer for BINFO's virtual function table. BINFO
8614 is part of the hierarchy dominated by T. If we're building a
8615 construction vtable, the ORIG_BINFO is the binfo we should use to
8616 find the actual function pointers to put in the vtable - but they
8617 can be overridden on the path to most-derived in the graph that
8618 ORIG_BINFO belongs. Otherwise,
8619 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
8620 BINFO that should be indicated by the RTTI information in the
8621 vtable; it will be a base class of T, rather than T itself, if we
8622 are building a construction vtable.
8623
8624 The value returned is a TREE_LIST suitable for wrapping in a
8625 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
8626 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
8627 number of non-function entries in the vtable.
8628
8629 It might seem that this function should never be called with a
8630 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
8631 base is always subsumed by a derived class vtable. However, when
8632 we are building construction vtables, we do build vtables for
8633 primary bases; we need these while the primary base is being
8634 constructed. */
8635
8636 static void
build_vtbl_initializer(tree binfo,tree orig_binfo,tree t,tree rtti_binfo,int * non_fn_entries_p,vec<constructor_elt,va_gc> ** inits)8637 build_vtbl_initializer (tree binfo,
8638 tree orig_binfo,
8639 tree t,
8640 tree rtti_binfo,
8641 int* non_fn_entries_p,
8642 vec<constructor_elt, va_gc> **inits)
8643 {
8644 tree v;
8645 vtbl_init_data vid;
8646 unsigned ix, jx;
8647 tree vbinfo;
8648 vec<tree, va_gc> *vbases;
8649 constructor_elt *e;
8650
8651 /* Initialize VID. */
8652 memset (&vid, 0, sizeof (vid));
8653 vid.binfo = binfo;
8654 vid.derived = t;
8655 vid.rtti_binfo = rtti_binfo;
8656 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
8657 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
8658 vid.generate_vcall_entries = true;
8659 /* The first vbase or vcall offset is at index -3 in the vtable. */
8660 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
8661
8662 /* Add entries to the vtable for RTTI. */
8663 build_rtti_vtbl_entries (binfo, &vid);
8664
8665 /* Create an array for keeping track of the functions we've
8666 processed. When we see multiple functions with the same
8667 signature, we share the vcall offsets. */
8668 vec_alloc (vid.fns, 32);
8669 /* Add the vcall and vbase offset entries. */
8670 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
8671
8672 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
8673 build_vbase_offset_vtbl_entries. */
8674 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
8675 vec_safe_iterate (vbases, ix, &vbinfo); ix++)
8676 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
8677
8678 /* If the target requires padding between data entries, add that now. */
8679 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
8680 {
8681 int n_entries = vec_safe_length (vid.inits);
8682
8683 vec_safe_grow (vid.inits, TARGET_VTABLE_DATA_ENTRY_DISTANCE * n_entries);
8684
8685 /* Move data entries into their new positions and add padding
8686 after the new positions. Iterate backwards so we don't
8687 overwrite entries that we would need to process later. */
8688 for (ix = n_entries - 1;
8689 vid.inits->iterate (ix, &e);
8690 ix--)
8691 {
8692 int j;
8693 int new_position = (TARGET_VTABLE_DATA_ENTRY_DISTANCE * ix
8694 + (TARGET_VTABLE_DATA_ENTRY_DISTANCE - 1));
8695
8696 (*vid.inits)[new_position] = *e;
8697
8698 for (j = 1; j < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++j)
8699 {
8700 constructor_elt *f = &(*vid.inits)[new_position - j];
8701 f->index = NULL_TREE;
8702 f->value = build1 (NOP_EXPR, vtable_entry_type,
8703 null_pointer_node);
8704 }
8705 }
8706 }
8707
8708 if (non_fn_entries_p)
8709 *non_fn_entries_p = vec_safe_length (vid.inits);
8710
8711 /* The initializers for virtual functions were built up in reverse
8712 order. Straighten them out and add them to the running list in one
8713 step. */
8714 jx = vec_safe_length (*inits);
8715 vec_safe_grow (*inits, jx + vid.inits->length ());
8716
8717 for (ix = vid.inits->length () - 1;
8718 vid.inits->iterate (ix, &e);
8719 ix--, jx++)
8720 (**inits)[jx] = *e;
8721
8722 /* Go through all the ordinary virtual functions, building up
8723 initializers. */
8724 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
8725 {
8726 tree delta;
8727 tree vcall_index;
8728 tree fn, fn_original;
8729 tree init = NULL_TREE;
8730
8731 fn = BV_FN (v);
8732 fn_original = fn;
8733 if (DECL_THUNK_P (fn))
8734 {
8735 if (!DECL_NAME (fn))
8736 finish_thunk (fn);
8737 if (THUNK_ALIAS (fn))
8738 {
8739 fn = THUNK_ALIAS (fn);
8740 BV_FN (v) = fn;
8741 }
8742 fn_original = THUNK_TARGET (fn);
8743 }
8744
8745 /* If the only definition of this function signature along our
8746 primary base chain is from a lost primary, this vtable slot will
8747 never be used, so just zero it out. This is important to avoid
8748 requiring extra thunks which cannot be generated with the function.
8749
8750 We first check this in update_vtable_entry_for_fn, so we handle
8751 restored primary bases properly; we also need to do it here so we
8752 zero out unused slots in ctor vtables, rather than filling them
8753 with erroneous values (though harmless, apart from relocation
8754 costs). */
8755 if (BV_LOST_PRIMARY (v))
8756 init = size_zero_node;
8757
8758 if (! init)
8759 {
8760 /* Pull the offset for `this', and the function to call, out of
8761 the list. */
8762 delta = BV_DELTA (v);
8763 vcall_index = BV_VCALL_INDEX (v);
8764
8765 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
8766 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
8767
8768 /* You can't call an abstract virtual function; it's abstract.
8769 So, we replace these functions with __pure_virtual. */
8770 if (DECL_PURE_VIRTUAL_P (fn_original))
8771 {
8772 fn = abort_fndecl;
8773 if (!TARGET_VTABLE_USES_DESCRIPTORS)
8774 {
8775 if (abort_fndecl_addr == NULL)
8776 abort_fndecl_addr
8777 = fold_convert (vfunc_ptr_type_node,
8778 build_fold_addr_expr (fn));
8779 init = abort_fndecl_addr;
8780 }
8781 }
8782 /* Likewise for deleted virtuals. */
8783 else if (DECL_DELETED_FN (fn_original))
8784 {
8785 fn = get_identifier ("__cxa_deleted_virtual");
8786 if (!get_global_value_if_present (fn, &fn))
8787 fn = push_library_fn (fn, (build_function_type_list
8788 (void_type_node, NULL_TREE)),
8789 NULL_TREE);
8790 if (!TARGET_VTABLE_USES_DESCRIPTORS)
8791 init = fold_convert (vfunc_ptr_type_node,
8792 build_fold_addr_expr (fn));
8793 }
8794 else
8795 {
8796 if (!integer_zerop (delta) || vcall_index)
8797 {
8798 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
8799 if (!DECL_NAME (fn))
8800 finish_thunk (fn);
8801 }
8802 /* Take the address of the function, considering it to be of an
8803 appropriate generic type. */
8804 if (!TARGET_VTABLE_USES_DESCRIPTORS)
8805 init = fold_convert (vfunc_ptr_type_node,
8806 build_fold_addr_expr (fn));
8807 }
8808 }
8809
8810 /* And add it to the chain of initializers. */
8811 if (TARGET_VTABLE_USES_DESCRIPTORS)
8812 {
8813 int i;
8814 if (init == size_zero_node)
8815 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
8816 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init);
8817 else
8818 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
8819 {
8820 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
8821 fn, build_int_cst (NULL_TREE, i));
8822 TREE_CONSTANT (fdesc) = 1;
8823
8824 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, fdesc);
8825 }
8826 }
8827 else
8828 CONSTRUCTOR_APPEND_ELT (*inits, NULL_TREE, init);
8829 }
8830 }
8831
8832 /* Adds to vid->inits the initializers for the vbase and vcall
8833 offsets in BINFO, which is in the hierarchy dominated by T. */
8834
8835 static void
build_vcall_and_vbase_vtbl_entries(tree binfo,vtbl_init_data * vid)8836 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
8837 {
8838 tree b;
8839
8840 /* If this is a derived class, we must first create entries
8841 corresponding to the primary base class. */
8842 b = get_primary_binfo (binfo);
8843 if (b)
8844 build_vcall_and_vbase_vtbl_entries (b, vid);
8845
8846 /* Add the vbase entries for this base. */
8847 build_vbase_offset_vtbl_entries (binfo, vid);
8848 /* Add the vcall entries for this base. */
8849 build_vcall_offset_vtbl_entries (binfo, vid);
8850 }
8851
8852 /* Returns the initializers for the vbase offset entries in the vtable
8853 for BINFO (which is part of the class hierarchy dominated by T), in
8854 reverse order. VBASE_OFFSET_INDEX gives the vtable index
8855 where the next vbase offset will go. */
8856
8857 static void
build_vbase_offset_vtbl_entries(tree binfo,vtbl_init_data * vid)8858 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
8859 {
8860 tree vbase;
8861 tree t;
8862 tree non_primary_binfo;
8863
8864 /* If there are no virtual baseclasses, then there is nothing to
8865 do. */
8866 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
8867 return;
8868
8869 t = vid->derived;
8870
8871 /* We might be a primary base class. Go up the inheritance hierarchy
8872 until we find the most derived class of which we are a primary base:
8873 it is the offset of that which we need to use. */
8874 non_primary_binfo = binfo;
8875 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
8876 {
8877 tree b;
8878
8879 /* If we have reached a virtual base, then it must be a primary
8880 base (possibly multi-level) of vid->binfo, or we wouldn't
8881 have called build_vcall_and_vbase_vtbl_entries for it. But it
8882 might be a lost primary, so just skip down to vid->binfo. */
8883 if (BINFO_VIRTUAL_P (non_primary_binfo))
8884 {
8885 non_primary_binfo = vid->binfo;
8886 break;
8887 }
8888
8889 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
8890 if (get_primary_binfo (b) != non_primary_binfo)
8891 break;
8892 non_primary_binfo = b;
8893 }
8894
8895 /* Go through the virtual bases, adding the offsets. */
8896 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
8897 vbase;
8898 vbase = TREE_CHAIN (vbase))
8899 {
8900 tree b;
8901 tree delta;
8902
8903 if (!BINFO_VIRTUAL_P (vbase))
8904 continue;
8905
8906 /* Find the instance of this virtual base in the complete
8907 object. */
8908 b = copied_binfo (vbase, binfo);
8909
8910 /* If we've already got an offset for this virtual base, we
8911 don't need another one. */
8912 if (BINFO_VTABLE_PATH_MARKED (b))
8913 continue;
8914 BINFO_VTABLE_PATH_MARKED (b) = 1;
8915
8916 /* Figure out where we can find this vbase offset. */
8917 delta = size_binop (MULT_EXPR,
8918 vid->index,
8919 convert (ssizetype,
8920 TYPE_SIZE_UNIT (vtable_entry_type)));
8921 if (vid->primary_vtbl_p)
8922 BINFO_VPTR_FIELD (b) = delta;
8923
8924 if (binfo != TYPE_BINFO (t))
8925 /* The vbase offset had better be the same. */
8926 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
8927
8928 /* The next vbase will come at a more negative offset. */
8929 vid->index = size_binop (MINUS_EXPR, vid->index,
8930 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
8931
8932 /* The initializer is the delta from BINFO to this virtual base.
8933 The vbase offsets go in reverse inheritance-graph order, and
8934 we are walking in inheritance graph order so these end up in
8935 the right order. */
8936 delta = size_diffop_loc (input_location,
8937 BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
8938
8939 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE,
8940 fold_build1_loc (input_location, NOP_EXPR,
8941 vtable_entry_type, delta));
8942 }
8943 }
8944
8945 /* Adds the initializers for the vcall offset entries in the vtable
8946 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
8947 to VID->INITS. */
8948
8949 static void
build_vcall_offset_vtbl_entries(tree binfo,vtbl_init_data * vid)8950 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
8951 {
8952 /* We only need these entries if this base is a virtual base. We
8953 compute the indices -- but do not add to the vtable -- when
8954 building the main vtable for a class. */
8955 if (binfo == TYPE_BINFO (vid->derived)
8956 || (BINFO_VIRTUAL_P (binfo)
8957 /* If BINFO is RTTI_BINFO, then (since BINFO does not
8958 correspond to VID->DERIVED), we are building a primary
8959 construction virtual table. Since this is a primary
8960 virtual table, we do not need the vcall offsets for
8961 BINFO. */
8962 && binfo != vid->rtti_binfo))
8963 {
8964 /* We need a vcall offset for each of the virtual functions in this
8965 vtable. For example:
8966
8967 class A { virtual void f (); };
8968 class B1 : virtual public A { virtual void f (); };
8969 class B2 : virtual public A { virtual void f (); };
8970 class C: public B1, public B2 { virtual void f (); };
8971
8972 A C object has a primary base of B1, which has a primary base of A. A
8973 C also has a secondary base of B2, which no longer has a primary base
8974 of A. So the B2-in-C construction vtable needs a secondary vtable for
8975 A, which will adjust the A* to a B2* to call f. We have no way of
8976 knowing what (or even whether) this offset will be when we define B2,
8977 so we store this "vcall offset" in the A sub-vtable and look it up in
8978 a "virtual thunk" for B2::f.
8979
8980 We need entries for all the functions in our primary vtable and
8981 in our non-virtual bases' secondary vtables. */
8982 vid->vbase = binfo;
8983 /* If we are just computing the vcall indices -- but do not need
8984 the actual entries -- not that. */
8985 if (!BINFO_VIRTUAL_P (binfo))
8986 vid->generate_vcall_entries = false;
8987 /* Now, walk through the non-virtual bases, adding vcall offsets. */
8988 add_vcall_offset_vtbl_entries_r (binfo, vid);
8989 }
8990 }
8991
8992 /* Build vcall offsets, starting with those for BINFO. */
8993
8994 static void
add_vcall_offset_vtbl_entries_r(tree binfo,vtbl_init_data * vid)8995 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
8996 {
8997 int i;
8998 tree primary_binfo;
8999 tree base_binfo;
9000
9001 /* Don't walk into virtual bases -- except, of course, for the
9002 virtual base for which we are building vcall offsets. Any
9003 primary virtual base will have already had its offsets generated
9004 through the recursion in build_vcall_and_vbase_vtbl_entries. */
9005 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
9006 return;
9007
9008 /* If BINFO has a primary base, process it first. */
9009 primary_binfo = get_primary_binfo (binfo);
9010 if (primary_binfo)
9011 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
9012
9013 /* Add BINFO itself to the list. */
9014 add_vcall_offset_vtbl_entries_1 (binfo, vid);
9015
9016 /* Scan the non-primary bases of BINFO. */
9017 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
9018 if (base_binfo != primary_binfo)
9019 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
9020 }
9021
9022 /* Called from build_vcall_offset_vtbl_entries_r. */
9023
9024 static void
add_vcall_offset_vtbl_entries_1(tree binfo,vtbl_init_data * vid)9025 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
9026 {
9027 /* Make entries for the rest of the virtuals. */
9028 if (abi_version_at_least (2))
9029 {
9030 tree orig_fn;
9031
9032 /* The ABI requires that the methods be processed in declaration
9033 order. G++ 3.2 used the order in the vtable. */
9034 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
9035 orig_fn;
9036 orig_fn = DECL_CHAIN (orig_fn))
9037 if (DECL_VINDEX (orig_fn))
9038 add_vcall_offset (orig_fn, binfo, vid);
9039 }
9040 else
9041 {
9042 tree derived_virtuals;
9043 tree base_virtuals;
9044 tree orig_virtuals;
9045 /* If BINFO is a primary base, the most derived class which has
9046 BINFO as a primary base; otherwise, just BINFO. */
9047 tree non_primary_binfo;
9048
9049 /* We might be a primary base class. Go up the inheritance hierarchy
9050 until we find the most derived class of which we are a primary base:
9051 it is the BINFO_VIRTUALS there that we need to consider. */
9052 non_primary_binfo = binfo;
9053 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
9054 {
9055 tree b;
9056
9057 /* If we have reached a virtual base, then it must be vid->vbase,
9058 because we ignore other virtual bases in
9059 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
9060 base (possibly multi-level) of vid->binfo, or we wouldn't
9061 have called build_vcall_and_vbase_vtbl_entries for it. But it
9062 might be a lost primary, so just skip down to vid->binfo. */
9063 if (BINFO_VIRTUAL_P (non_primary_binfo))
9064 {
9065 gcc_assert (non_primary_binfo == vid->vbase);
9066 non_primary_binfo = vid->binfo;
9067 break;
9068 }
9069
9070 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
9071 if (get_primary_binfo (b) != non_primary_binfo)
9072 break;
9073 non_primary_binfo = b;
9074 }
9075
9076 if (vid->ctor_vtbl_p)
9077 /* For a ctor vtable we need the equivalent binfo within the hierarchy
9078 where rtti_binfo is the most derived type. */
9079 non_primary_binfo
9080 = original_binfo (non_primary_binfo, vid->rtti_binfo);
9081
9082 for (base_virtuals = BINFO_VIRTUALS (binfo),
9083 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
9084 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
9085 base_virtuals;
9086 base_virtuals = TREE_CHAIN (base_virtuals),
9087 derived_virtuals = TREE_CHAIN (derived_virtuals),
9088 orig_virtuals = TREE_CHAIN (orig_virtuals))
9089 {
9090 tree orig_fn;
9091
9092 /* Find the declaration that originally caused this function to
9093 be present in BINFO_TYPE (binfo). */
9094 orig_fn = BV_FN (orig_virtuals);
9095
9096 /* When processing BINFO, we only want to generate vcall slots for
9097 function slots introduced in BINFO. So don't try to generate
9098 one if the function isn't even defined in BINFO. */
9099 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
9100 continue;
9101
9102 add_vcall_offset (orig_fn, binfo, vid);
9103 }
9104 }
9105 }
9106
9107 /* Add a vcall offset entry for ORIG_FN to the vtable. */
9108
9109 static void
add_vcall_offset(tree orig_fn,tree binfo,vtbl_init_data * vid)9110 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
9111 {
9112 size_t i;
9113 tree vcall_offset;
9114 tree derived_entry;
9115
9116 /* If there is already an entry for a function with the same
9117 signature as FN, then we do not need a second vcall offset.
9118 Check the list of functions already present in the derived
9119 class vtable. */
9120 FOR_EACH_VEC_SAFE_ELT (vid->fns, i, derived_entry)
9121 {
9122 if (same_signature_p (derived_entry, orig_fn)
9123 /* We only use one vcall offset for virtual destructors,
9124 even though there are two virtual table entries. */
9125 || (DECL_DESTRUCTOR_P (derived_entry)
9126 && DECL_DESTRUCTOR_P (orig_fn)))
9127 return;
9128 }
9129
9130 /* If we are building these vcall offsets as part of building
9131 the vtable for the most derived class, remember the vcall
9132 offset. */
9133 if (vid->binfo == TYPE_BINFO (vid->derived))
9134 {
9135 tree_pair_s elt = {orig_fn, vid->index};
9136 vec_safe_push (CLASSTYPE_VCALL_INDICES (vid->derived), elt);
9137 }
9138
9139 /* The next vcall offset will be found at a more negative
9140 offset. */
9141 vid->index = size_binop (MINUS_EXPR, vid->index,
9142 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
9143
9144 /* Keep track of this function. */
9145 vec_safe_push (vid->fns, orig_fn);
9146
9147 if (vid->generate_vcall_entries)
9148 {
9149 tree base;
9150 tree fn;
9151
9152 /* Find the overriding function. */
9153 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
9154 if (fn == error_mark_node)
9155 vcall_offset = build_zero_cst (vtable_entry_type);
9156 else
9157 {
9158 base = TREE_VALUE (fn);
9159
9160 /* The vbase we're working on is a primary base of
9161 vid->binfo. But it might be a lost primary, so its
9162 BINFO_OFFSET might be wrong, so we just use the
9163 BINFO_OFFSET from vid->binfo. */
9164 vcall_offset = size_diffop_loc (input_location,
9165 BINFO_OFFSET (base),
9166 BINFO_OFFSET (vid->binfo));
9167 vcall_offset = fold_build1_loc (input_location,
9168 NOP_EXPR, vtable_entry_type,
9169 vcall_offset);
9170 }
9171 /* Add the initializer to the vtable. */
9172 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, vcall_offset);
9173 }
9174 }
9175
9176 /* Return vtbl initializers for the RTTI entries corresponding to the
9177 BINFO's vtable. The RTTI entries should indicate the object given
9178 by VID->rtti_binfo. */
9179
9180 static void
build_rtti_vtbl_entries(tree binfo,vtbl_init_data * vid)9181 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
9182 {
9183 tree b;
9184 tree t;
9185 tree offset;
9186 tree decl;
9187 tree init;
9188
9189 t = BINFO_TYPE (vid->rtti_binfo);
9190
9191 /* To find the complete object, we will first convert to our most
9192 primary base, and then add the offset in the vtbl to that value. */
9193 b = binfo;
9194 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
9195 && !BINFO_LOST_PRIMARY_P (b))
9196 {
9197 tree primary_base;
9198
9199 primary_base = get_primary_binfo (b);
9200 gcc_assert (BINFO_PRIMARY_P (primary_base)
9201 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
9202 b = primary_base;
9203 }
9204 offset = size_diffop_loc (input_location,
9205 BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
9206
9207 /* The second entry is the address of the typeinfo object. */
9208 if (flag_rtti)
9209 decl = build_address (get_tinfo_decl (t));
9210 else
9211 decl = integer_zero_node;
9212
9213 /* Convert the declaration to a type that can be stored in the
9214 vtable. */
9215 init = build_nop (vfunc_ptr_type_node, decl);
9216 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init);
9217
9218 /* Add the offset-to-top entry. It comes earlier in the vtable than
9219 the typeinfo entry. Convert the offset to look like a
9220 function pointer, so that we can put it in the vtable. */
9221 init = build_nop (vfunc_ptr_type_node, offset);
9222 CONSTRUCTOR_APPEND_ELT (vid->inits, NULL_TREE, init);
9223 }
9224
9225 /* TRUE iff TYPE is uniquely derived from PARENT. Ignores
9226 accessibility. */
9227
9228 bool
uniquely_derived_from_p(tree parent,tree type)9229 uniquely_derived_from_p (tree parent, tree type)
9230 {
9231 tree base = lookup_base (type, parent, ba_unique, NULL, tf_none);
9232 return base && base != error_mark_node;
9233 }
9234
9235 /* TRUE iff TYPE is publicly & uniquely derived from PARENT. */
9236
9237 bool
publicly_uniquely_derived_p(tree parent,tree type)9238 publicly_uniquely_derived_p (tree parent, tree type)
9239 {
9240 tree base = lookup_base (type, parent, ba_ignore_scope | ba_check,
9241 NULL, tf_none);
9242 return base && base != error_mark_node;
9243 }
9244
9245 #include "gt-cp-class.h"
9246