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