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[official-gcc.git] / gcc / cp / class.c
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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
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
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.
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.
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/>. */
24 /* High-level class interface. */
26 #include "config.h"
27 #include "system.h"
28 #include "coretypes.h"
29 #include "tm.h"
30 #include "tree.h"
31 #include "cp-tree.h"
32 #include "flags.h"
33 #include "rtl.h"
34 #include "output.h"
35 #include "toplev.h"
36 #include "target.h"
37 #include "convert.h"
38 #include "cgraph.h"
39 #include "tree-dump.h"
41 /* The number of nested classes being processed. If we are not in the
42 scope of any class, this is zero. */
44 int current_class_depth;
46 /* In order to deal with nested classes, we keep a stack of classes.
47 The topmost entry is the innermost class, and is the entry at index
48 CURRENT_CLASS_DEPTH */
50 typedef struct class_stack_node {
51 /* The name of the class. */
52 tree name;
54 /* The _TYPE node for the class. */
55 tree type;
57 /* The access specifier pending for new declarations in the scope of
58 this class. */
59 tree access;
61 /* If were defining TYPE, the names used in this class. */
62 splay_tree names_used;
64 /* Nonzero if this class is no longer open, because of a call to
65 push_to_top_level. */
66 size_t hidden;
67 }* class_stack_node_t;
69 typedef struct vtbl_init_data_s
71 /* The base for which we're building initializers. */
72 tree binfo;
73 /* The type of the most-derived type. */
74 tree derived;
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
77 tree rtti_binfo;
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
80 tree inits;
81 /* The last (i.e., most negative) entry in INITS. */
82 tree* last_init;
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
85 tree vbase;
86 /* The functions in vbase for which we have already provided vcall
87 offsets. */
88 VEC(tree,gc) *fns;
89 /* The vtable index of the next vcall or vbase offset. */
90 tree index;
91 /* Nonzero if we are building the initializer for the primary
92 vtable. */
93 int primary_vtbl_p;
94 /* Nonzero if we are building the initializer for a construction
95 vtable. */
96 int ctor_vtbl_p;
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
99 bool generate_vcall_entries;
100 } vtbl_init_data;
102 /* The type of a function passed to walk_subobject_offsets. */
103 typedef int (*subobject_offset_fn) (tree, tree, splay_tree);
105 /* The stack itself. This is a dynamically resized array. The
106 number of elements allocated is CURRENT_CLASS_STACK_SIZE. */
107 static int current_class_stack_size;
108 static class_stack_node_t current_class_stack;
110 /* The size of the largest empty class seen in this translation unit. */
111 static GTY (()) tree sizeof_biggest_empty_class;
113 /* An array of all local classes present in this translation unit, in
114 declaration order. */
115 VEC(tree,gc) *local_classes;
117 static tree get_vfield_name (tree);
118 static void finish_struct_anon (tree);
119 static tree get_vtable_name (tree);
120 static tree get_basefndecls (tree, tree);
121 static int build_primary_vtable (tree, tree);
122 static int build_secondary_vtable (tree);
123 static void finish_vtbls (tree);
124 static void modify_vtable_entry (tree, tree, tree, tree, tree *);
125 static void finish_struct_bits (tree);
126 static int alter_access (tree, tree, tree);
127 static void handle_using_decl (tree, tree);
128 static tree dfs_modify_vtables (tree, void *);
129 static tree modify_all_vtables (tree, tree);
130 static void determine_primary_bases (tree);
131 static void finish_struct_methods (tree);
132 static void maybe_warn_about_overly_private_class (tree);
133 static int method_name_cmp (const void *, const void *);
134 static int resort_method_name_cmp (const void *, const void *);
135 static void add_implicitly_declared_members (tree, int, int);
136 static tree fixed_type_or_null (tree, int *, int *);
137 static tree build_simple_base_path (tree expr, tree binfo);
138 static tree build_vtbl_ref_1 (tree, tree);
139 static tree build_vtbl_initializer (tree, tree, tree, tree, int *);
140 static int count_fields (tree);
141 static int add_fields_to_record_type (tree, struct sorted_fields_type*, int);
142 static bool check_bitfield_decl (tree);
143 static void check_field_decl (tree, tree, int *, int *, int *);
144 static void check_field_decls (tree, tree *, int *, int *);
145 static tree *build_base_field (record_layout_info, tree, splay_tree, tree *);
146 static void build_base_fields (record_layout_info, splay_tree, tree *);
147 static void check_methods (tree);
148 static void remove_zero_width_bit_fields (tree);
149 static void check_bases (tree, int *, int *);
150 static void check_bases_and_members (tree);
151 static tree create_vtable_ptr (tree, tree *);
152 static void include_empty_classes (record_layout_info);
153 static void layout_class_type (tree, tree *);
154 static void fixup_pending_inline (tree);
155 static void fixup_inline_methods (tree);
156 static void propagate_binfo_offsets (tree, tree);
157 static void layout_virtual_bases (record_layout_info, splay_tree);
158 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
159 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
160 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
161 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
162 static void add_vcall_offset (tree, tree, vtbl_init_data *);
163 static void layout_vtable_decl (tree, int);
164 static tree dfs_find_final_overrider_pre (tree, void *);
165 static tree dfs_find_final_overrider_post (tree, void *);
166 static tree find_final_overrider (tree, tree, tree);
167 static int make_new_vtable (tree, tree);
168 static tree get_primary_binfo (tree);
169 static int maybe_indent_hierarchy (FILE *, int, int);
170 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
171 static void dump_class_hierarchy (tree);
172 static void dump_class_hierarchy_1 (FILE *, int, tree);
173 static void dump_array (FILE *, tree);
174 static void dump_vtable (tree, tree, tree);
175 static void dump_vtt (tree, tree);
176 static void dump_thunk (FILE *, int, tree);
177 static tree build_vtable (tree, tree, tree);
178 static void initialize_vtable (tree, tree);
179 static void layout_nonempty_base_or_field (record_layout_info,
180 tree, tree, splay_tree);
181 static tree end_of_class (tree, int);
182 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree);
183 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
184 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
185 tree);
186 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
187 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
188 static void clone_constructors_and_destructors (tree);
189 static tree build_clone (tree, tree);
190 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
191 static void build_ctor_vtbl_group (tree, tree);
192 static void build_vtt (tree);
193 static tree binfo_ctor_vtable (tree);
194 static tree *build_vtt_inits (tree, tree, tree *, tree *);
195 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
196 static tree dfs_fixup_binfo_vtbls (tree, void *);
197 static int record_subobject_offset (tree, tree, splay_tree);
198 static int check_subobject_offset (tree, tree, splay_tree);
199 static int walk_subobject_offsets (tree, subobject_offset_fn,
200 tree, splay_tree, tree, int);
201 static void record_subobject_offsets (tree, tree, splay_tree, bool);
202 static int layout_conflict_p (tree, tree, splay_tree, int);
203 static int splay_tree_compare_integer_csts (splay_tree_key k1,
204 splay_tree_key k2);
205 static void warn_about_ambiguous_bases (tree);
206 static bool type_requires_array_cookie (tree);
207 static bool contains_empty_class_p (tree);
208 static bool base_derived_from (tree, tree);
209 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
210 static tree end_of_base (tree);
211 static tree get_vcall_index (tree, tree);
213 /* Variables shared between class.c and call.c. */
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
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. */
235 tree
236 build_base_path (enum tree_code code,
237 tree expr,
238 tree binfo,
239 int nonnull)
241 tree v_binfo = NULL_TREE;
242 tree d_binfo = NULL_TREE;
243 tree probe;
244 tree offset;
245 tree target_type;
246 tree null_test = NULL;
247 tree ptr_target_type;
248 int fixed_type_p;
249 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
250 bool has_empty = false;
251 bool virtual_access;
253 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
254 return error_mark_node;
256 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
258 d_binfo = probe;
259 if (is_empty_class (BINFO_TYPE (probe)))
260 has_empty = true;
261 if (!v_binfo && BINFO_VIRTUAL_P (probe))
262 v_binfo = probe;
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
266 if (want_pointer)
267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
269 gcc_assert ((code == MINUS_EXPR
270 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
271 || (code == PLUS_EXPR
272 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
274 if (binfo == d_binfo)
275 /* Nothing to do. */
276 return expr;
278 if (code == MINUS_EXPR && v_binfo)
280 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
281 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
282 return error_mark_node;
285 if (!want_pointer)
286 /* This must happen before the call to save_expr. */
287 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error);
289 offset = BINFO_OFFSET (binfo);
290 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
291 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
293 /* Do we need to look in the vtable for the real offset? */
294 virtual_access = (v_binfo && fixed_type_p <= 0);
296 /* Don't bother with the calculations inside sizeof; they'll ICE if the
297 source type is incomplete and the pointer value doesn't matter. */
298 if (skip_evaluation)
300 expr = build_nop (build_pointer_type (target_type), expr);
301 if (!want_pointer)
302 expr = build_indirect_ref (EXPR_LOCATION (expr), expr, NULL);
303 return expr;
306 /* Do we need to check for a null pointer? */
307 if (want_pointer && !nonnull)
309 /* If we know the conversion will not actually change the value
310 of EXPR, then we can avoid testing the expression for NULL.
311 We have to avoid generating a COMPONENT_REF for a base class
312 field, because other parts of the compiler know that such
313 expressions are always non-NULL. */
314 if (!virtual_access && integer_zerop (offset))
316 tree class_type;
317 /* TARGET_TYPE has been extracted from BINFO, and, is
318 therefore always cv-unqualified. Extract the
319 cv-qualifiers from EXPR so that the expression returned
320 matches the input. */
321 class_type = TREE_TYPE (TREE_TYPE (expr));
322 target_type
323 = cp_build_qualified_type (target_type,
324 cp_type_quals (class_type));
325 return build_nop (build_pointer_type (target_type), expr);
327 null_test = error_mark_node;
330 /* Protect against multiple evaluation if necessary. */
331 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
332 expr = save_expr (expr);
334 /* Now that we've saved expr, build the real null test. */
335 if (null_test)
337 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
338 null_test = fold_build2 (NE_EXPR, boolean_type_node,
339 expr, zero);
342 /* If this is a simple base reference, express it as a COMPONENT_REF. */
343 if (code == PLUS_EXPR && !virtual_access
344 /* We don't build base fields for empty bases, and they aren't very
345 interesting to the optimizers anyway. */
346 && !has_empty)
348 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
349 expr = build_simple_base_path (expr, binfo);
350 if (want_pointer)
351 expr = build_address (expr);
352 target_type = TREE_TYPE (expr);
353 goto out;
356 if (virtual_access)
358 /* Going via virtual base V_BINFO. We need the static offset
359 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
360 V_BINFO. That offset is an entry in D_BINFO's vtable. */
361 tree v_offset;
363 if (fixed_type_p < 0 && in_base_initializer)
365 /* In a base member initializer, we cannot rely on the
366 vtable being set up. We have to indirect via the
367 vtt_parm. */
368 tree t;
370 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
371 t = build_pointer_type (t);
372 v_offset = convert (t, current_vtt_parm);
373 v_offset = cp_build_indirect_ref (v_offset, NULL,
374 tf_warning_or_error);
376 else
377 v_offset = build_vfield_ref (cp_build_indirect_ref (expr, NULL,
378 tf_warning_or_error),
379 TREE_TYPE (TREE_TYPE (expr)));
381 v_offset = build2 (POINTER_PLUS_EXPR, TREE_TYPE (v_offset),
382 v_offset, fold_convert (sizetype, BINFO_VPTR_FIELD (v_binfo)));
383 v_offset = build1 (NOP_EXPR,
384 build_pointer_type (ptrdiff_type_node),
385 v_offset);
386 v_offset = cp_build_indirect_ref (v_offset, NULL, tf_warning_or_error);
387 TREE_CONSTANT (v_offset) = 1;
389 offset = convert_to_integer (ptrdiff_type_node,
390 size_diffop (offset,
391 BINFO_OFFSET (v_binfo)));
393 if (!integer_zerop (offset))
394 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
396 if (fixed_type_p < 0)
397 /* Negative fixed_type_p means this is a constructor or destructor;
398 virtual base layout is fixed in in-charge [cd]tors, but not in
399 base [cd]tors. */
400 offset = build3 (COND_EXPR, ptrdiff_type_node,
401 build2 (EQ_EXPR, boolean_type_node,
402 current_in_charge_parm, integer_zero_node),
403 v_offset,
404 convert_to_integer (ptrdiff_type_node,
405 BINFO_OFFSET (binfo)));
406 else
407 offset = v_offset;
410 target_type = cp_build_qualified_type
411 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
412 ptr_target_type = build_pointer_type (target_type);
413 if (want_pointer)
414 target_type = ptr_target_type;
416 expr = build1 (NOP_EXPR, ptr_target_type, expr);
418 if (!integer_zerop (offset))
420 offset = fold_convert (sizetype, offset);
421 if (code == MINUS_EXPR)
422 offset = fold_build1 (NEGATE_EXPR, sizetype, offset);
423 expr = build2 (POINTER_PLUS_EXPR, ptr_target_type, expr, offset);
425 else
426 null_test = NULL;
428 if (!want_pointer)
429 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
431 out:
432 if (null_test)
433 expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
434 fold_build1 (NOP_EXPR, target_type,
435 integer_zero_node));
437 return expr;
440 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
441 Perform a derived-to-base conversion by recursively building up a
442 sequence of COMPONENT_REFs to the appropriate base fields. */
444 static tree
445 build_simple_base_path (tree expr, tree binfo)
447 tree type = BINFO_TYPE (binfo);
448 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
449 tree field;
451 if (d_binfo == NULL_TREE)
453 tree temp;
455 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
457 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
458 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
459 an lvalue in the front end; only _DECLs and _REFs are lvalues
460 in the back end. */
461 temp = unary_complex_lvalue (ADDR_EXPR, expr);
462 if (temp)
463 expr = cp_build_indirect_ref (temp, NULL, tf_warning_or_error);
465 return expr;
468 /* Recurse. */
469 expr = build_simple_base_path (expr, d_binfo);
471 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
472 field; field = TREE_CHAIN (field))
473 /* Is this the base field created by build_base_field? */
474 if (TREE_CODE (field) == FIELD_DECL
475 && DECL_FIELD_IS_BASE (field)
476 && TREE_TYPE (field) == type)
478 /* We don't use build_class_member_access_expr here, as that
479 has unnecessary checks, and more importantly results in
480 recursive calls to dfs_walk_once. */
481 int type_quals = cp_type_quals (TREE_TYPE (expr));
483 expr = build3 (COMPONENT_REF,
484 cp_build_qualified_type (type, type_quals),
485 expr, field, NULL_TREE);
486 expr = fold_if_not_in_template (expr);
488 /* Mark the expression const or volatile, as appropriate.
489 Even though we've dealt with the type above, we still have
490 to mark the expression itself. */
491 if (type_quals & TYPE_QUAL_CONST)
492 TREE_READONLY (expr) = 1;
493 if (type_quals & TYPE_QUAL_VOLATILE)
494 TREE_THIS_VOLATILE (expr) = 1;
496 return expr;
499 /* Didn't find the base field?!? */
500 gcc_unreachable ();
503 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
504 type is a class type or a pointer to a class type. In the former
505 case, TYPE is also a class type; in the latter it is another
506 pointer type. If CHECK_ACCESS is true, an error message is emitted
507 if TYPE is inaccessible. If OBJECT has pointer type, the value is
508 assumed to be non-NULL. */
510 tree
511 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
513 tree binfo;
514 tree object_type;
516 if (TYPE_PTR_P (TREE_TYPE (object)))
518 object_type = TREE_TYPE (TREE_TYPE (object));
519 type = TREE_TYPE (type);
521 else
522 object_type = TREE_TYPE (object);
524 binfo = lookup_base (object_type, type,
525 check_access ? ba_check : ba_unique,
526 NULL);
527 if (!binfo || binfo == error_mark_node)
528 return error_mark_node;
530 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
533 /* EXPR is an expression with unqualified class type. BASE is a base
534 binfo of that class type. Returns EXPR, converted to the BASE
535 type. This function assumes that EXPR is the most derived class;
536 therefore virtual bases can be found at their static offsets. */
538 tree
539 convert_to_base_statically (tree expr, tree base)
541 tree expr_type;
543 expr_type = TREE_TYPE (expr);
544 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
546 tree pointer_type;
548 pointer_type = build_pointer_type (expr_type);
550 /* We use fold_build2 and fold_convert below to simplify the trees
551 provided to the optimizers. It is not safe to call these functions
552 when processing a template because they do not handle C++-specific
553 trees. */
554 gcc_assert (!processing_template_decl);
555 expr = cp_build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1,
556 tf_warning_or_error);
557 if (!integer_zerop (BINFO_OFFSET (base)))
558 expr = fold_build2 (POINTER_PLUS_EXPR, pointer_type, expr,
559 fold_convert (sizetype, BINFO_OFFSET (base)));
560 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr);
561 expr = build_fold_indirect_ref (expr);
564 return expr;
568 tree
569 build_vfield_ref (tree datum, tree type)
571 tree vfield, vcontext;
573 if (datum == error_mark_node)
574 return error_mark_node;
576 /* First, convert to the requested type. */
577 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
578 datum = convert_to_base (datum, type, /*check_access=*/false,
579 /*nonnull=*/true);
581 /* Second, the requested type may not be the owner of its own vptr.
582 If not, convert to the base class that owns it. We cannot use
583 convert_to_base here, because VCONTEXT may appear more than once
584 in the inheritance hierarchy of TYPE, and thus direct conversion
585 between the types may be ambiguous. Following the path back up
586 one step at a time via primary bases avoids the problem. */
587 vfield = TYPE_VFIELD (type);
588 vcontext = DECL_CONTEXT (vfield);
589 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
591 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
592 type = TREE_TYPE (datum);
595 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
598 /* Given an object INSTANCE, return an expression which yields the
599 vtable element corresponding to INDEX. There are many special
600 cases for INSTANCE which we take care of here, mainly to avoid
601 creating extra tree nodes when we don't have to. */
603 static tree
604 build_vtbl_ref_1 (tree instance, tree idx)
606 tree aref;
607 tree vtbl = NULL_TREE;
609 /* Try to figure out what a reference refers to, and
610 access its virtual function table directly. */
612 int cdtorp = 0;
613 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
615 tree basetype = non_reference (TREE_TYPE (instance));
617 if (fixed_type && !cdtorp)
619 tree binfo = lookup_base (fixed_type, basetype,
620 ba_unique | ba_quiet, NULL);
621 if (binfo)
622 vtbl = unshare_expr (BINFO_VTABLE (binfo));
625 if (!vtbl)
626 vtbl = build_vfield_ref (instance, basetype);
629 aref = build_array_ref (vtbl, idx, input_location);
630 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
632 return aref;
635 tree
636 build_vtbl_ref (tree instance, tree idx)
638 tree aref = build_vtbl_ref_1 (instance, idx);
640 return aref;
643 /* Given a stable object pointer INSTANCE_PTR, return an expression which
644 yields a function pointer corresponding to vtable element INDEX. */
646 tree
647 build_vfn_ref (tree instance_ptr, tree idx)
649 tree aref;
651 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, 0,
652 tf_warning_or_error),
653 idx);
655 /* When using function descriptors, the address of the
656 vtable entry is treated as a function pointer. */
657 if (TARGET_VTABLE_USES_DESCRIPTORS)
658 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
659 cp_build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1,
660 tf_warning_or_error));
662 /* Remember this as a method reference, for later devirtualization. */
663 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
665 return aref;
668 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
669 for the given TYPE. */
671 static tree
672 get_vtable_name (tree type)
674 return mangle_vtbl_for_type (type);
677 /* DECL is an entity associated with TYPE, like a virtual table or an
678 implicitly generated constructor. Determine whether or not DECL
679 should have external or internal linkage at the object file
680 level. This routine does not deal with COMDAT linkage and other
681 similar complexities; it simply sets TREE_PUBLIC if it possible for
682 entities in other translation units to contain copies of DECL, in
683 the abstract. */
685 void
686 set_linkage_according_to_type (tree type, tree decl)
688 /* If TYPE involves a local class in a function with internal
689 linkage, then DECL should have internal linkage too. Other local
690 classes have no linkage -- but if their containing functions
691 have external linkage, it makes sense for DECL to have external
692 linkage too. That will allow template definitions to be merged,
693 for example. */
694 if (no_linkage_check (type, /*relaxed_p=*/true))
696 TREE_PUBLIC (decl) = 0;
697 DECL_INTERFACE_KNOWN (decl) = 1;
699 else
700 TREE_PUBLIC (decl) = 1;
703 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
704 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
705 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
707 static tree
708 build_vtable (tree class_type, tree name, tree vtable_type)
710 tree decl;
712 decl = build_lang_decl (VAR_DECL, name, vtable_type);
713 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
714 now to avoid confusion in mangle_decl. */
715 SET_DECL_ASSEMBLER_NAME (decl, name);
716 DECL_CONTEXT (decl) = class_type;
717 DECL_ARTIFICIAL (decl) = 1;
718 TREE_STATIC (decl) = 1;
719 TREE_READONLY (decl) = 1;
720 DECL_VIRTUAL_P (decl) = 1;
721 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
722 DECL_VTABLE_OR_VTT_P (decl) = 1;
723 /* At one time the vtable info was grabbed 2 words at a time. This
724 fails on sparc unless you have 8-byte alignment. (tiemann) */
725 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
726 DECL_ALIGN (decl));
727 set_linkage_according_to_type (class_type, decl);
728 /* The vtable has not been defined -- yet. */
729 DECL_EXTERNAL (decl) = 1;
730 DECL_NOT_REALLY_EXTERN (decl) = 1;
732 /* Mark the VAR_DECL node representing the vtable itself as a
733 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
734 is rather important that such things be ignored because any
735 effort to actually generate DWARF for them will run into
736 trouble when/if we encounter code like:
738 #pragma interface
739 struct S { virtual void member (); };
741 because the artificial declaration of the vtable itself (as
742 manufactured by the g++ front end) will say that the vtable is
743 a static member of `S' but only *after* the debug output for
744 the definition of `S' has already been output. This causes
745 grief because the DWARF entry for the definition of the vtable
746 will try to refer back to an earlier *declaration* of the
747 vtable as a static member of `S' and there won't be one. We
748 might be able to arrange to have the "vtable static member"
749 attached to the member list for `S' before the debug info for
750 `S' get written (which would solve the problem) but that would
751 require more intrusive changes to the g++ front end. */
752 DECL_IGNORED_P (decl) = 1;
754 return decl;
757 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
758 or even complete. If this does not exist, create it. If COMPLETE is
759 nonzero, then complete the definition of it -- that will render it
760 impossible to actually build the vtable, but is useful to get at those
761 which are known to exist in the runtime. */
763 tree
764 get_vtable_decl (tree type, int complete)
766 tree decl;
768 if (CLASSTYPE_VTABLES (type))
769 return CLASSTYPE_VTABLES (type);
771 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
772 CLASSTYPE_VTABLES (type) = decl;
774 if (complete)
776 DECL_EXTERNAL (decl) = 1;
777 finish_decl (decl, NULL_TREE, NULL_TREE, NULL_TREE);
780 return decl;
783 /* Build the primary virtual function table for TYPE. If BINFO is
784 non-NULL, build the vtable starting with the initial approximation
785 that it is the same as the one which is the head of the association
786 list. Returns a nonzero value if a new vtable is actually
787 created. */
789 static int
790 build_primary_vtable (tree binfo, tree type)
792 tree decl;
793 tree virtuals;
795 decl = get_vtable_decl (type, /*complete=*/0);
797 if (binfo)
799 if (BINFO_NEW_VTABLE_MARKED (binfo))
800 /* We have already created a vtable for this base, so there's
801 no need to do it again. */
802 return 0;
804 virtuals = copy_list (BINFO_VIRTUALS (binfo));
805 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
806 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
807 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
809 else
811 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
812 virtuals = NULL_TREE;
815 #ifdef GATHER_STATISTICS
816 n_vtables += 1;
817 n_vtable_elems += list_length (virtuals);
818 #endif
820 /* Initialize the association list for this type, based
821 on our first approximation. */
822 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
823 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
824 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
825 return 1;
828 /* Give BINFO a new virtual function table which is initialized
829 with a skeleton-copy of its original initialization. The only
830 entry that changes is the `delta' entry, so we can really
831 share a lot of structure.
833 FOR_TYPE is the most derived type which caused this table to
834 be needed.
836 Returns nonzero if we haven't met BINFO before.
838 The order in which vtables are built (by calling this function) for
839 an object must remain the same, otherwise a binary incompatibility
840 can result. */
842 static int
843 build_secondary_vtable (tree binfo)
845 if (BINFO_NEW_VTABLE_MARKED (binfo))
846 /* We already created a vtable for this base. There's no need to
847 do it again. */
848 return 0;
850 /* Remember that we've created a vtable for this BINFO, so that we
851 don't try to do so again. */
852 SET_BINFO_NEW_VTABLE_MARKED (binfo);
854 /* Make fresh virtual list, so we can smash it later. */
855 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
857 /* Secondary vtables are laid out as part of the same structure as
858 the primary vtable. */
859 BINFO_VTABLE (binfo) = NULL_TREE;
860 return 1;
863 /* Create a new vtable for BINFO which is the hierarchy dominated by
864 T. Return nonzero if we actually created a new vtable. */
866 static int
867 make_new_vtable (tree t, tree binfo)
869 if (binfo == TYPE_BINFO (t))
870 /* In this case, it is *type*'s vtable we are modifying. We start
871 with the approximation that its vtable is that of the
872 immediate base class. */
873 return build_primary_vtable (binfo, t);
874 else
875 /* This is our very own copy of `basetype' to play with. Later,
876 we will fill in all the virtual functions that override the
877 virtual functions in these base classes which are not defined
878 by the current type. */
879 return build_secondary_vtable (binfo);
882 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
883 (which is in the hierarchy dominated by T) list FNDECL as its
884 BV_FN. DELTA is the required constant adjustment from the `this'
885 pointer where the vtable entry appears to the `this' required when
886 the function is actually called. */
888 static void
889 modify_vtable_entry (tree t,
890 tree binfo,
891 tree fndecl,
892 tree delta,
893 tree *virtuals)
895 tree v;
897 v = *virtuals;
899 if (fndecl != BV_FN (v)
900 || !tree_int_cst_equal (delta, BV_DELTA (v)))
902 /* We need a new vtable for BINFO. */
903 if (make_new_vtable (t, binfo))
905 /* If we really did make a new vtable, we also made a copy
906 of the BINFO_VIRTUALS list. Now, we have to find the
907 corresponding entry in that list. */
908 *virtuals = BINFO_VIRTUALS (binfo);
909 while (BV_FN (*virtuals) != BV_FN (v))
910 *virtuals = TREE_CHAIN (*virtuals);
911 v = *virtuals;
914 BV_DELTA (v) = delta;
915 BV_VCALL_INDEX (v) = NULL_TREE;
916 BV_FN (v) = fndecl;
921 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
922 the USING_DECL naming METHOD. Returns true if the method could be
923 added to the method vec. */
925 bool
926 add_method (tree type, tree method, tree using_decl)
928 unsigned slot;
929 tree overload;
930 bool template_conv_p = false;
931 bool conv_p;
932 VEC(tree,gc) *method_vec;
933 bool complete_p;
934 bool insert_p = false;
935 tree current_fns;
936 tree fns;
938 if (method == error_mark_node)
939 return false;
941 complete_p = COMPLETE_TYPE_P (type);
942 conv_p = DECL_CONV_FN_P (method);
943 if (conv_p)
944 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
945 && DECL_TEMPLATE_CONV_FN_P (method));
947 method_vec = CLASSTYPE_METHOD_VEC (type);
948 if (!method_vec)
950 /* Make a new method vector. We start with 8 entries. We must
951 allocate at least two (for constructors and destructors), and
952 we're going to end up with an assignment operator at some
953 point as well. */
954 method_vec = VEC_alloc (tree, gc, 8);
955 /* Create slots for constructors and destructors. */
956 VEC_quick_push (tree, method_vec, NULL_TREE);
957 VEC_quick_push (tree, method_vec, NULL_TREE);
958 CLASSTYPE_METHOD_VEC (type) = method_vec;
961 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
962 grok_special_member_properties (method);
964 /* Constructors and destructors go in special slots. */
965 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
966 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
967 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
969 slot = CLASSTYPE_DESTRUCTOR_SLOT;
971 if (TYPE_FOR_JAVA (type))
973 if (!DECL_ARTIFICIAL (method))
974 error ("Java class %qT cannot have a destructor", type);
975 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
976 error ("Java class %qT cannot have an implicit non-trivial "
977 "destructor",
978 type);
981 else
983 tree m;
985 insert_p = true;
986 /* See if we already have an entry with this name. */
987 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
988 VEC_iterate (tree, method_vec, slot, m);
989 ++slot)
991 m = OVL_CURRENT (m);
992 if (template_conv_p)
994 if (TREE_CODE (m) == TEMPLATE_DECL
995 && DECL_TEMPLATE_CONV_FN_P (m))
996 insert_p = false;
997 break;
999 if (conv_p && !DECL_CONV_FN_P (m))
1000 break;
1001 if (DECL_NAME (m) == DECL_NAME (method))
1003 insert_p = false;
1004 break;
1006 if (complete_p
1007 && !DECL_CONV_FN_P (m)
1008 && DECL_NAME (m) > DECL_NAME (method))
1009 break;
1012 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
1014 /* Check to see if we've already got this method. */
1015 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
1017 tree fn = OVL_CURRENT (fns);
1018 tree fn_type;
1019 tree method_type;
1020 tree parms1;
1021 tree parms2;
1023 if (TREE_CODE (fn) != TREE_CODE (method))
1024 continue;
1026 /* [over.load] Member function declarations with the
1027 same name and the same parameter types cannot be
1028 overloaded if any of them is a static member
1029 function declaration.
1031 [namespace.udecl] When a using-declaration brings names
1032 from a base class into a derived class scope, member
1033 functions in the derived class override and/or hide member
1034 functions with the same name and parameter types in a base
1035 class (rather than conflicting). */
1036 fn_type = TREE_TYPE (fn);
1037 method_type = TREE_TYPE (method);
1038 parms1 = TYPE_ARG_TYPES (fn_type);
1039 parms2 = TYPE_ARG_TYPES (method_type);
1041 /* Compare the quals on the 'this' parm. Don't compare
1042 the whole types, as used functions are treated as
1043 coming from the using class in overload resolution. */
1044 if (! DECL_STATIC_FUNCTION_P (fn)
1045 && ! DECL_STATIC_FUNCTION_P (method)
1046 && TREE_TYPE (TREE_VALUE (parms1)) != error_mark_node
1047 && TREE_TYPE (TREE_VALUE (parms2)) != error_mark_node
1048 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1049 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1050 continue;
1052 /* For templates, the return type and template parameters
1053 must be identical. */
1054 if (TREE_CODE (fn) == TEMPLATE_DECL
1055 && (!same_type_p (TREE_TYPE (fn_type),
1056 TREE_TYPE (method_type))
1057 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1058 DECL_TEMPLATE_PARMS (method))))
1059 continue;
1061 if (! DECL_STATIC_FUNCTION_P (fn))
1062 parms1 = TREE_CHAIN (parms1);
1063 if (! DECL_STATIC_FUNCTION_P (method))
1064 parms2 = TREE_CHAIN (parms2);
1066 if (compparms (parms1, parms2)
1067 && (!DECL_CONV_FN_P (fn)
1068 || same_type_p (TREE_TYPE (fn_type),
1069 TREE_TYPE (method_type))))
1071 if (using_decl)
1073 if (DECL_CONTEXT (fn) == type)
1074 /* Defer to the local function. */
1075 return false;
1076 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1077 error ("repeated using declaration %q+D", using_decl);
1078 else
1079 error ("using declaration %q+D conflicts with a previous using declaration",
1080 using_decl);
1082 else
1084 error ("%q+#D cannot be overloaded", method);
1085 error ("with %q+#D", fn);
1088 /* We don't call duplicate_decls here to merge the
1089 declarations because that will confuse things if the
1090 methods have inline definitions. In particular, we
1091 will crash while processing the definitions. */
1092 return false;
1096 /* A class should never have more than one destructor. */
1097 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1098 return false;
1100 /* Add the new binding. */
1101 overload = build_overload (method, current_fns);
1103 if (conv_p)
1104 TYPE_HAS_CONVERSION (type) = 1;
1105 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1106 push_class_level_binding (DECL_NAME (method), overload);
1108 if (insert_p)
1110 bool reallocated;
1112 /* We only expect to add few methods in the COMPLETE_P case, so
1113 just make room for one more method in that case. */
1114 if (complete_p)
1115 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1);
1116 else
1117 reallocated = VEC_reserve (tree, gc, method_vec, 1);
1118 if (reallocated)
1119 CLASSTYPE_METHOD_VEC (type) = method_vec;
1120 if (slot == VEC_length (tree, method_vec))
1121 VEC_quick_push (tree, method_vec, overload);
1122 else
1123 VEC_quick_insert (tree, method_vec, slot, overload);
1125 else
1126 /* Replace the current slot. */
1127 VEC_replace (tree, method_vec, slot, overload);
1128 return true;
1131 /* Subroutines of finish_struct. */
1133 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1134 legit, otherwise return 0. */
1136 static int
1137 alter_access (tree t, tree fdecl, tree access)
1139 tree elem;
1141 if (!DECL_LANG_SPECIFIC (fdecl))
1142 retrofit_lang_decl (fdecl);
1144 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1146 elem = purpose_member (t, DECL_ACCESS (fdecl));
1147 if (elem)
1149 if (TREE_VALUE (elem) != access)
1151 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1152 error ("conflicting access specifications for method"
1153 " %q+D, ignored", TREE_TYPE (fdecl));
1154 else
1155 error ("conflicting access specifications for field %qE, ignored",
1156 DECL_NAME (fdecl));
1158 else
1160 /* They're changing the access to the same thing they changed
1161 it to before. That's OK. */
1165 else
1167 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl);
1168 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1169 return 1;
1171 return 0;
1174 /* Process the USING_DECL, which is a member of T. */
1176 static void
1177 handle_using_decl (tree using_decl, tree t)
1179 tree decl = USING_DECL_DECLS (using_decl);
1180 tree name = DECL_NAME (using_decl);
1181 tree access
1182 = TREE_PRIVATE (using_decl) ? access_private_node
1183 : TREE_PROTECTED (using_decl) ? access_protected_node
1184 : access_public_node;
1185 tree flist = NULL_TREE;
1186 tree old_value;
1188 gcc_assert (!processing_template_decl && decl);
1190 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1191 if (old_value)
1193 if (is_overloaded_fn (old_value))
1194 old_value = OVL_CURRENT (old_value);
1196 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1197 /* OK */;
1198 else
1199 old_value = NULL_TREE;
1202 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1204 if (is_overloaded_fn (decl))
1205 flist = decl;
1207 if (! old_value)
1209 else if (is_overloaded_fn (old_value))
1211 if (flist)
1212 /* It's OK to use functions from a base when there are functions with
1213 the same name already present in the current class. */;
1214 else
1216 error ("%q+D invalid in %q#T", using_decl, t);
1217 error (" because of local method %q+#D with same name",
1218 OVL_CURRENT (old_value));
1219 return;
1222 else if (!DECL_ARTIFICIAL (old_value))
1224 error ("%q+D invalid in %q#T", using_decl, t);
1225 error (" because of local member %q+#D with same name", old_value);
1226 return;
1229 /* Make type T see field decl FDECL with access ACCESS. */
1230 if (flist)
1231 for (; flist; flist = OVL_NEXT (flist))
1233 add_method (t, OVL_CURRENT (flist), using_decl);
1234 alter_access (t, OVL_CURRENT (flist), access);
1236 else
1237 alter_access (t, decl, access);
1240 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1241 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1242 properties of the bases. */
1244 static void
1245 check_bases (tree t,
1246 int* cant_have_const_ctor_p,
1247 int* no_const_asn_ref_p)
1249 int i;
1250 int seen_non_virtual_nearly_empty_base_p;
1251 tree base_binfo;
1252 tree binfo;
1254 seen_non_virtual_nearly_empty_base_p = 0;
1256 for (binfo = TYPE_BINFO (t), i = 0;
1257 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1259 tree basetype = TREE_TYPE (base_binfo);
1261 gcc_assert (COMPLETE_TYPE_P (basetype));
1263 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1264 here because the case of virtual functions but non-virtual
1265 dtor is handled in finish_struct_1. */
1266 if (!TYPE_POLYMORPHIC_P (basetype))
1267 warning (OPT_Weffc__,
1268 "base class %q#T has a non-virtual destructor", basetype);
1270 /* If the base class doesn't have copy constructors or
1271 assignment operators that take const references, then the
1272 derived class cannot have such a member automatically
1273 generated. */
1274 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1275 *cant_have_const_ctor_p = 1;
1276 if (TYPE_HAS_ASSIGN_REF (basetype)
1277 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1278 *no_const_asn_ref_p = 1;
1280 if (BINFO_VIRTUAL_P (base_binfo))
1281 /* A virtual base does not effect nearly emptiness. */
1283 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1285 if (seen_non_virtual_nearly_empty_base_p)
1286 /* And if there is more than one nearly empty base, then the
1287 derived class is not nearly empty either. */
1288 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1289 else
1290 /* Remember we've seen one. */
1291 seen_non_virtual_nearly_empty_base_p = 1;
1293 else if (!is_empty_class (basetype))
1294 /* If the base class is not empty or nearly empty, then this
1295 class cannot be nearly empty. */
1296 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1298 /* A lot of properties from the bases also apply to the derived
1299 class. */
1300 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1301 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1302 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1303 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1304 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1305 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1306 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1307 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1308 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1309 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (basetype);
1313 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1314 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1315 that have had a nearly-empty virtual primary base stolen by some
1316 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1317 T. */
1319 static void
1320 determine_primary_bases (tree t)
1322 unsigned i;
1323 tree primary = NULL_TREE;
1324 tree type_binfo = TYPE_BINFO (t);
1325 tree base_binfo;
1327 /* Determine the primary bases of our bases. */
1328 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1329 base_binfo = TREE_CHAIN (base_binfo))
1331 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1333 /* See if we're the non-virtual primary of our inheritance
1334 chain. */
1335 if (!BINFO_VIRTUAL_P (base_binfo))
1337 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1338 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1340 if (parent_primary
1341 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1342 BINFO_TYPE (parent_primary)))
1343 /* We are the primary binfo. */
1344 BINFO_PRIMARY_P (base_binfo) = 1;
1346 /* Determine if we have a virtual primary base, and mark it so.
1348 if (primary && BINFO_VIRTUAL_P (primary))
1350 tree this_primary = copied_binfo (primary, base_binfo);
1352 if (BINFO_PRIMARY_P (this_primary))
1353 /* Someone already claimed this base. */
1354 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1355 else
1357 tree delta;
1359 BINFO_PRIMARY_P (this_primary) = 1;
1360 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1362 /* A virtual binfo might have been copied from within
1363 another hierarchy. As we're about to use it as a
1364 primary base, make sure the offsets match. */
1365 delta = size_diffop (convert (ssizetype,
1366 BINFO_OFFSET (base_binfo)),
1367 convert (ssizetype,
1368 BINFO_OFFSET (this_primary)));
1370 propagate_binfo_offsets (this_primary, delta);
1375 /* First look for a dynamic direct non-virtual base. */
1376 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1378 tree basetype = BINFO_TYPE (base_binfo);
1380 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1382 primary = base_binfo;
1383 goto found;
1387 /* A "nearly-empty" virtual base class can be the primary base
1388 class, if no non-virtual polymorphic base can be found. Look for
1389 a nearly-empty virtual dynamic base that is not already a primary
1390 base of something in the hierarchy. If there is no such base,
1391 just pick the first nearly-empty virtual base. */
1393 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1394 base_binfo = TREE_CHAIN (base_binfo))
1395 if (BINFO_VIRTUAL_P (base_binfo)
1396 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1398 if (!BINFO_PRIMARY_P (base_binfo))
1400 /* Found one that is not primary. */
1401 primary = base_binfo;
1402 goto found;
1404 else if (!primary)
1405 /* Remember the first candidate. */
1406 primary = base_binfo;
1409 found:
1410 /* If we've got a primary base, use it. */
1411 if (primary)
1413 tree basetype = BINFO_TYPE (primary);
1415 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1416 if (BINFO_PRIMARY_P (primary))
1417 /* We are stealing a primary base. */
1418 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1419 BINFO_PRIMARY_P (primary) = 1;
1420 if (BINFO_VIRTUAL_P (primary))
1422 tree delta;
1424 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1425 /* A virtual binfo might have been copied from within
1426 another hierarchy. As we're about to use it as a primary
1427 base, make sure the offsets match. */
1428 delta = size_diffop (ssize_int (0),
1429 convert (ssizetype, BINFO_OFFSET (primary)));
1431 propagate_binfo_offsets (primary, delta);
1434 primary = TYPE_BINFO (basetype);
1436 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1437 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1438 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1442 /* Update the variant types of T. */
1444 void
1445 fixup_type_variants (tree t)
1447 tree variants;
1449 if (!t)
1450 return;
1452 for (variants = TYPE_NEXT_VARIANT (t);
1453 variants;
1454 variants = TYPE_NEXT_VARIANT (variants))
1456 /* These fields are in the _TYPE part of the node, not in
1457 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1458 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
1459 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1460 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1461 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1463 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1465 TYPE_BINFO (variants) = TYPE_BINFO (t);
1467 /* Copy whatever these are holding today. */
1468 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1469 TYPE_METHODS (variants) = TYPE_METHODS (t);
1470 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1472 /* All variants of a class have the same attributes. */
1473 TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t);
1478 /* Set memoizing fields and bits of T (and its variants) for later
1479 use. */
1481 static void
1482 finish_struct_bits (tree t)
1484 /* Fix up variants (if any). */
1485 fixup_type_variants (t);
1487 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1488 /* For a class w/o baseclasses, 'finish_struct' has set
1489 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1490 Similarly for a class whose base classes do not have vtables.
1491 When neither of these is true, we might have removed abstract
1492 virtuals (by providing a definition), added some (by declaring
1493 new ones), or redeclared ones from a base class. We need to
1494 recalculate what's really an abstract virtual at this point (by
1495 looking in the vtables). */
1496 get_pure_virtuals (t);
1498 /* If this type has a copy constructor or a destructor, force its
1499 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1500 nonzero. This will cause it to be passed by invisible reference
1501 and prevent it from being returned in a register. */
1502 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1504 tree variants;
1505 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1506 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1508 SET_TYPE_MODE (variants, BLKmode);
1509 TREE_ADDRESSABLE (variants) = 1;
1514 /* Issue warnings about T having private constructors, but no friends,
1515 and so forth.
1517 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1518 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1519 non-private static member functions. */
1521 static void
1522 maybe_warn_about_overly_private_class (tree t)
1524 int has_member_fn = 0;
1525 int has_nonprivate_method = 0;
1526 tree fn;
1528 if (!warn_ctor_dtor_privacy
1529 /* If the class has friends, those entities might create and
1530 access instances, so we should not warn. */
1531 || (CLASSTYPE_FRIEND_CLASSES (t)
1532 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1533 /* We will have warned when the template was declared; there's
1534 no need to warn on every instantiation. */
1535 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1536 /* There's no reason to even consider warning about this
1537 class. */
1538 return;
1540 /* We only issue one warning, if more than one applies, because
1541 otherwise, on code like:
1543 class A {
1544 // Oops - forgot `public:'
1545 A();
1546 A(const A&);
1547 ~A();
1550 we warn several times about essentially the same problem. */
1552 /* Check to see if all (non-constructor, non-destructor) member
1553 functions are private. (Since there are no friends or
1554 non-private statics, we can't ever call any of the private member
1555 functions.) */
1556 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1557 /* We're not interested in compiler-generated methods; they don't
1558 provide any way to call private members. */
1559 if (!DECL_ARTIFICIAL (fn))
1561 if (!TREE_PRIVATE (fn))
1563 if (DECL_STATIC_FUNCTION_P (fn))
1564 /* A non-private static member function is just like a
1565 friend; it can create and invoke private member
1566 functions, and be accessed without a class
1567 instance. */
1568 return;
1570 has_nonprivate_method = 1;
1571 /* Keep searching for a static member function. */
1573 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1574 has_member_fn = 1;
1577 if (!has_nonprivate_method && has_member_fn)
1579 /* There are no non-private methods, and there's at least one
1580 private member function that isn't a constructor or
1581 destructor. (If all the private members are
1582 constructors/destructors we want to use the code below that
1583 issues error messages specifically referring to
1584 constructors/destructors.) */
1585 unsigned i;
1586 tree binfo = TYPE_BINFO (t);
1588 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1589 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1591 has_nonprivate_method = 1;
1592 break;
1594 if (!has_nonprivate_method)
1596 warning (OPT_Wctor_dtor_privacy,
1597 "all member functions in class %qT are private", t);
1598 return;
1602 /* Even if some of the member functions are non-private, the class
1603 won't be useful for much if all the constructors or destructors
1604 are private: such an object can never be created or destroyed. */
1605 fn = CLASSTYPE_DESTRUCTORS (t);
1606 if (fn && TREE_PRIVATE (fn))
1608 warning (OPT_Wctor_dtor_privacy,
1609 "%q#T only defines a private destructor and has no friends",
1611 return;
1614 /* Warn about classes that have private constructors and no friends. */
1615 if (TYPE_HAS_USER_CONSTRUCTOR (t)
1616 /* Implicitly generated constructors are always public. */
1617 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1618 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1620 int nonprivate_ctor = 0;
1622 /* If a non-template class does not define a copy
1623 constructor, one is defined for it, enabling it to avoid
1624 this warning. For a template class, this does not
1625 happen, and so we would normally get a warning on:
1627 template <class T> class C { private: C(); };
1629 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1630 complete non-template or fully instantiated classes have this
1631 flag set. */
1632 if (!TYPE_HAS_INIT_REF (t))
1633 nonprivate_ctor = 1;
1634 else
1635 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1637 tree ctor = OVL_CURRENT (fn);
1638 /* Ideally, we wouldn't count copy constructors (or, in
1639 fact, any constructor that takes an argument of the
1640 class type as a parameter) because such things cannot
1641 be used to construct an instance of the class unless
1642 you already have one. But, for now at least, we're
1643 more generous. */
1644 if (! TREE_PRIVATE (ctor))
1646 nonprivate_ctor = 1;
1647 break;
1651 if (nonprivate_ctor == 0)
1653 warning (OPT_Wctor_dtor_privacy,
1654 "%q#T only defines private constructors and has no friends",
1656 return;
1661 static struct {
1662 gt_pointer_operator new_value;
1663 void *cookie;
1664 } resort_data;
1666 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1668 static int
1669 method_name_cmp (const void* m1_p, const void* m2_p)
1671 const tree *const m1 = (const tree *) m1_p;
1672 const tree *const m2 = (const tree *) m2_p;
1674 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1675 return 0;
1676 if (*m1 == NULL_TREE)
1677 return -1;
1678 if (*m2 == NULL_TREE)
1679 return 1;
1680 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1681 return -1;
1682 return 1;
1685 /* This routine compares two fields like method_name_cmp but using the
1686 pointer operator in resort_field_decl_data. */
1688 static int
1689 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1691 const tree *const m1 = (const tree *) m1_p;
1692 const tree *const m2 = (const tree *) m2_p;
1693 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1694 return 0;
1695 if (*m1 == NULL_TREE)
1696 return -1;
1697 if (*m2 == NULL_TREE)
1698 return 1;
1700 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1701 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1702 resort_data.new_value (&d1, resort_data.cookie);
1703 resort_data.new_value (&d2, resort_data.cookie);
1704 if (d1 < d2)
1705 return -1;
1707 return 1;
1710 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1712 void
1713 resort_type_method_vec (void* obj,
1714 void* orig_obj ATTRIBUTE_UNUSED ,
1715 gt_pointer_operator new_value,
1716 void* cookie)
1718 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1719 int len = VEC_length (tree, method_vec);
1720 size_t slot;
1721 tree fn;
1723 /* The type conversion ops have to live at the front of the vec, so we
1724 can't sort them. */
1725 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1726 VEC_iterate (tree, method_vec, slot, fn);
1727 ++slot)
1728 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1729 break;
1731 if (len - slot > 1)
1733 resort_data.new_value = new_value;
1734 resort_data.cookie = cookie;
1735 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1736 resort_method_name_cmp);
1740 /* Warn about duplicate methods in fn_fields.
1742 Sort methods that are not special (i.e., constructors, destructors,
1743 and type conversion operators) so that we can find them faster in
1744 search. */
1746 static void
1747 finish_struct_methods (tree t)
1749 tree fn_fields;
1750 VEC(tree,gc) *method_vec;
1751 int slot, len;
1753 method_vec = CLASSTYPE_METHOD_VEC (t);
1754 if (!method_vec)
1755 return;
1757 len = VEC_length (tree, method_vec);
1759 /* Clear DECL_IN_AGGR_P for all functions. */
1760 for (fn_fields = TYPE_METHODS (t); fn_fields;
1761 fn_fields = TREE_CHAIN (fn_fields))
1762 DECL_IN_AGGR_P (fn_fields) = 0;
1764 /* Issue warnings about private constructors and such. If there are
1765 no methods, then some public defaults are generated. */
1766 maybe_warn_about_overly_private_class (t);
1768 /* The type conversion ops have to live at the front of the vec, so we
1769 can't sort them. */
1770 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1771 VEC_iterate (tree, method_vec, slot, fn_fields);
1772 ++slot)
1773 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1774 break;
1775 if (len - slot > 1)
1776 qsort (VEC_address (tree, method_vec) + slot,
1777 len-slot, sizeof (tree), method_name_cmp);
1780 /* Make BINFO's vtable have N entries, including RTTI entries,
1781 vbase and vcall offsets, etc. Set its type and call the back end
1782 to lay it out. */
1784 static void
1785 layout_vtable_decl (tree binfo, int n)
1787 tree atype;
1788 tree vtable;
1790 atype = build_cplus_array_type (vtable_entry_type,
1791 build_index_type (size_int (n - 1)));
1792 layout_type (atype);
1794 /* We may have to grow the vtable. */
1795 vtable = get_vtbl_decl_for_binfo (binfo);
1796 if (!same_type_p (TREE_TYPE (vtable), atype))
1798 TREE_TYPE (vtable) = atype;
1799 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1800 layout_decl (vtable, 0);
1804 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1805 have the same signature. */
1808 same_signature_p (const_tree fndecl, const_tree base_fndecl)
1810 /* One destructor overrides another if they are the same kind of
1811 destructor. */
1812 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1813 && special_function_p (base_fndecl) == special_function_p (fndecl))
1814 return 1;
1815 /* But a non-destructor never overrides a destructor, nor vice
1816 versa, nor do different kinds of destructors override
1817 one-another. For example, a complete object destructor does not
1818 override a deleting destructor. */
1819 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1820 return 0;
1822 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1823 || (DECL_CONV_FN_P (fndecl)
1824 && DECL_CONV_FN_P (base_fndecl)
1825 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1826 DECL_CONV_FN_TYPE (base_fndecl))))
1828 tree types, base_types;
1829 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1830 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1831 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1832 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1833 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1834 return 1;
1836 return 0;
1839 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1840 subobject. */
1842 static bool
1843 base_derived_from (tree derived, tree base)
1845 tree probe;
1847 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1849 if (probe == derived)
1850 return true;
1851 else if (BINFO_VIRTUAL_P (probe))
1852 /* If we meet a virtual base, we can't follow the inheritance
1853 any more. See if the complete type of DERIVED contains
1854 such a virtual base. */
1855 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1856 != NULL_TREE);
1858 return false;
1861 typedef struct find_final_overrider_data_s {
1862 /* The function for which we are trying to find a final overrider. */
1863 tree fn;
1864 /* The base class in which the function was declared. */
1865 tree declaring_base;
1866 /* The candidate overriders. */
1867 tree candidates;
1868 /* Path to most derived. */
1869 VEC(tree,heap) *path;
1870 } find_final_overrider_data;
1872 /* Add the overrider along the current path to FFOD->CANDIDATES.
1873 Returns true if an overrider was found; false otherwise. */
1875 static bool
1876 dfs_find_final_overrider_1 (tree binfo,
1877 find_final_overrider_data *ffod,
1878 unsigned depth)
1880 tree method;
1882 /* If BINFO is not the most derived type, try a more derived class.
1883 A definition there will overrider a definition here. */
1884 if (depth)
1886 depth--;
1887 if (dfs_find_final_overrider_1
1888 (VEC_index (tree, ffod->path, depth), ffod, depth))
1889 return true;
1892 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1893 if (method)
1895 tree *candidate = &ffod->candidates;
1897 /* Remove any candidates overridden by this new function. */
1898 while (*candidate)
1900 /* If *CANDIDATE overrides METHOD, then METHOD
1901 cannot override anything else on the list. */
1902 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1903 return true;
1904 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1905 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1906 *candidate = TREE_CHAIN (*candidate);
1907 else
1908 candidate = &TREE_CHAIN (*candidate);
1911 /* Add the new function. */
1912 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1913 return true;
1916 return false;
1919 /* Called from find_final_overrider via dfs_walk. */
1921 static tree
1922 dfs_find_final_overrider_pre (tree binfo, void *data)
1924 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1926 if (binfo == ffod->declaring_base)
1927 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1928 VEC_safe_push (tree, heap, ffod->path, binfo);
1930 return NULL_TREE;
1933 static tree
1934 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1936 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1937 VEC_pop (tree, ffod->path);
1939 return NULL_TREE;
1942 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1943 FN and whose TREE_VALUE is the binfo for the base where the
1944 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1945 DERIVED) is the base object in which FN is declared. */
1947 static tree
1948 find_final_overrider (tree derived, tree binfo, tree fn)
1950 find_final_overrider_data ffod;
1952 /* Getting this right is a little tricky. This is valid:
1954 struct S { virtual void f (); };
1955 struct T { virtual void f (); };
1956 struct U : public S, public T { };
1958 even though calling `f' in `U' is ambiguous. But,
1960 struct R { virtual void f(); };
1961 struct S : virtual public R { virtual void f (); };
1962 struct T : virtual public R { virtual void f (); };
1963 struct U : public S, public T { };
1965 is not -- there's no way to decide whether to put `S::f' or
1966 `T::f' in the vtable for `R'.
1968 The solution is to look at all paths to BINFO. If we find
1969 different overriders along any two, then there is a problem. */
1970 if (DECL_THUNK_P (fn))
1971 fn = THUNK_TARGET (fn);
1973 /* Determine the depth of the hierarchy. */
1974 ffod.fn = fn;
1975 ffod.declaring_base = binfo;
1976 ffod.candidates = NULL_TREE;
1977 ffod.path = VEC_alloc (tree, heap, 30);
1979 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1980 dfs_find_final_overrider_post, &ffod);
1982 VEC_free (tree, heap, ffod.path);
1984 /* If there was no winner, issue an error message. */
1985 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1986 return error_mark_node;
1988 return ffod.candidates;
1991 /* Return the index of the vcall offset for FN when TYPE is used as a
1992 virtual base. */
1994 static tree
1995 get_vcall_index (tree fn, tree type)
1997 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
1998 tree_pair_p p;
1999 unsigned ix;
2001 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
2002 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2003 || same_signature_p (fn, p->purpose))
2004 return p->value;
2006 /* There should always be an appropriate index. */
2007 gcc_unreachable ();
2010 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2011 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2012 corresponding position in the BINFO_VIRTUALS list. */
2014 static void
2015 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2016 unsigned ix)
2018 tree b;
2019 tree overrider;
2020 tree delta;
2021 tree virtual_base;
2022 tree first_defn;
2023 tree overrider_fn, overrider_target;
2024 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2025 tree over_return, base_return;
2026 bool lost = false;
2028 /* Find the nearest primary base (possibly binfo itself) which defines
2029 this function; this is the class the caller will convert to when
2030 calling FN through BINFO. */
2031 for (b = binfo; ; b = get_primary_binfo (b))
2033 gcc_assert (b);
2034 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2035 break;
2037 /* The nearest definition is from a lost primary. */
2038 if (BINFO_LOST_PRIMARY_P (b))
2039 lost = true;
2041 first_defn = b;
2043 /* Find the final overrider. */
2044 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2045 if (overrider == error_mark_node)
2047 error ("no unique final overrider for %qD in %qT", target_fn, t);
2048 return;
2050 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2052 /* Check for adjusting covariant return types. */
2053 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2054 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2056 if (POINTER_TYPE_P (over_return)
2057 && TREE_CODE (over_return) == TREE_CODE (base_return)
2058 && CLASS_TYPE_P (TREE_TYPE (over_return))
2059 && CLASS_TYPE_P (TREE_TYPE (base_return))
2060 /* If the overrider is invalid, don't even try. */
2061 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2063 /* If FN is a covariant thunk, we must figure out the adjustment
2064 to the final base FN was converting to. As OVERRIDER_TARGET might
2065 also be converting to the return type of FN, we have to
2066 combine the two conversions here. */
2067 tree fixed_offset, virtual_offset;
2069 over_return = TREE_TYPE (over_return);
2070 base_return = TREE_TYPE (base_return);
2072 if (DECL_THUNK_P (fn))
2074 gcc_assert (DECL_RESULT_THUNK_P (fn));
2075 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2076 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2078 else
2079 fixed_offset = virtual_offset = NULL_TREE;
2081 if (virtual_offset)
2082 /* Find the equivalent binfo within the return type of the
2083 overriding function. We will want the vbase offset from
2084 there. */
2085 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2086 over_return);
2087 else if (!same_type_ignoring_top_level_qualifiers_p
2088 (over_return, base_return))
2090 /* There was no existing virtual thunk (which takes
2091 precedence). So find the binfo of the base function's
2092 return type within the overriding function's return type.
2093 We cannot call lookup base here, because we're inside a
2094 dfs_walk, and will therefore clobber the BINFO_MARKED
2095 flags. Fortunately we know the covariancy is valid (it
2096 has already been checked), so we can just iterate along
2097 the binfos, which have been chained in inheritance graph
2098 order. Of course it is lame that we have to repeat the
2099 search here anyway -- we should really be caching pieces
2100 of the vtable and avoiding this repeated work. */
2101 tree thunk_binfo, base_binfo;
2103 /* Find the base binfo within the overriding function's
2104 return type. We will always find a thunk_binfo, except
2105 when the covariancy is invalid (which we will have
2106 already diagnosed). */
2107 for (base_binfo = TYPE_BINFO (base_return),
2108 thunk_binfo = TYPE_BINFO (over_return);
2109 thunk_binfo;
2110 thunk_binfo = TREE_CHAIN (thunk_binfo))
2111 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2112 BINFO_TYPE (base_binfo)))
2113 break;
2115 /* See if virtual inheritance is involved. */
2116 for (virtual_offset = thunk_binfo;
2117 virtual_offset;
2118 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2119 if (BINFO_VIRTUAL_P (virtual_offset))
2120 break;
2122 if (virtual_offset
2123 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2125 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2127 if (virtual_offset)
2129 /* We convert via virtual base. Adjust the fixed
2130 offset to be from there. */
2131 offset = size_diffop
2132 (offset, convert
2133 (ssizetype, BINFO_OFFSET (virtual_offset)));
2135 if (fixed_offset)
2136 /* There was an existing fixed offset, this must be
2137 from the base just converted to, and the base the
2138 FN was thunking to. */
2139 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2140 else
2141 fixed_offset = offset;
2145 if (fixed_offset || virtual_offset)
2146 /* Replace the overriding function with a covariant thunk. We
2147 will emit the overriding function in its own slot as
2148 well. */
2149 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2150 fixed_offset, virtual_offset);
2152 else
2153 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) ||
2154 !DECL_THUNK_P (fn));
2156 /* Assume that we will produce a thunk that convert all the way to
2157 the final overrider, and not to an intermediate virtual base. */
2158 virtual_base = NULL_TREE;
2160 /* See if we can convert to an intermediate virtual base first, and then
2161 use the vcall offset located there to finish the conversion. */
2162 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2164 /* If we find the final overrider, then we can stop
2165 walking. */
2166 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2167 BINFO_TYPE (TREE_VALUE (overrider))))
2168 break;
2170 /* If we find a virtual base, and we haven't yet found the
2171 overrider, then there is a virtual base between the
2172 declaring base (first_defn) and the final overrider. */
2173 if (BINFO_VIRTUAL_P (b))
2175 virtual_base = b;
2176 break;
2180 if (overrider_fn != overrider_target && !virtual_base)
2182 /* The ABI specifies that a covariant thunk includes a mangling
2183 for a this pointer adjustment. This-adjusting thunks that
2184 override a function from a virtual base have a vcall
2185 adjustment. When the virtual base in question is a primary
2186 virtual base, we know the adjustments are zero, (and in the
2187 non-covariant case, we would not use the thunk).
2188 Unfortunately we didn't notice this could happen, when
2189 designing the ABI and so never mandated that such a covariant
2190 thunk should be emitted. Because we must use the ABI mandated
2191 name, we must continue searching from the binfo where we
2192 found the most recent definition of the function, towards the
2193 primary binfo which first introduced the function into the
2194 vtable. If that enters a virtual base, we must use a vcall
2195 this-adjusting thunk. Bleah! */
2196 tree probe = first_defn;
2198 while ((probe = get_primary_binfo (probe))
2199 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2200 if (BINFO_VIRTUAL_P (probe))
2201 virtual_base = probe;
2203 if (virtual_base)
2204 /* Even if we find a virtual base, the correct delta is
2205 between the overrider and the binfo we're building a vtable
2206 for. */
2207 goto virtual_covariant;
2210 /* Compute the constant adjustment to the `this' pointer. The
2211 `this' pointer, when this function is called, will point at BINFO
2212 (or one of its primary bases, which are at the same offset). */
2213 if (virtual_base)
2214 /* The `this' pointer needs to be adjusted from the declaration to
2215 the nearest virtual base. */
2216 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2217 convert (ssizetype, BINFO_OFFSET (first_defn)));
2218 else if (lost)
2219 /* If the nearest definition is in a lost primary, we don't need an
2220 entry in our vtable. Except possibly in a constructor vtable,
2221 if we happen to get our primary back. In that case, the offset
2222 will be zero, as it will be a primary base. */
2223 delta = size_zero_node;
2224 else
2225 /* The `this' pointer needs to be adjusted from pointing to
2226 BINFO to pointing at the base where the final overrider
2227 appears. */
2228 virtual_covariant:
2229 delta = size_diffop (convert (ssizetype,
2230 BINFO_OFFSET (TREE_VALUE (overrider))),
2231 convert (ssizetype, BINFO_OFFSET (binfo)));
2233 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2235 if (virtual_base)
2236 BV_VCALL_INDEX (*virtuals)
2237 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2238 else
2239 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2242 /* Called from modify_all_vtables via dfs_walk. */
2244 static tree
2245 dfs_modify_vtables (tree binfo, void* data)
2247 tree t = (tree) data;
2248 tree virtuals;
2249 tree old_virtuals;
2250 unsigned ix;
2252 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2253 /* A base without a vtable needs no modification, and its bases
2254 are uninteresting. */
2255 return dfs_skip_bases;
2257 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2258 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2259 /* Don't do the primary vtable, if it's new. */
2260 return NULL_TREE;
2262 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2263 /* There's no need to modify the vtable for a non-virtual primary
2264 base; we're not going to use that vtable anyhow. We do still
2265 need to do this for virtual primary bases, as they could become
2266 non-primary in a construction vtable. */
2267 return NULL_TREE;
2269 make_new_vtable (t, binfo);
2271 /* Now, go through each of the virtual functions in the virtual
2272 function table for BINFO. Find the final overrider, and update
2273 the BINFO_VIRTUALS list appropriately. */
2274 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2275 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2276 virtuals;
2277 ix++, virtuals = TREE_CHAIN (virtuals),
2278 old_virtuals = TREE_CHAIN (old_virtuals))
2279 update_vtable_entry_for_fn (t,
2280 binfo,
2281 BV_FN (old_virtuals),
2282 &virtuals, ix);
2284 return NULL_TREE;
2287 /* Update all of the primary and secondary vtables for T. Create new
2288 vtables as required, and initialize their RTTI information. Each
2289 of the functions in VIRTUALS is declared in T and may override a
2290 virtual function from a base class; find and modify the appropriate
2291 entries to point to the overriding functions. Returns a list, in
2292 declaration order, of the virtual functions that are declared in T,
2293 but do not appear in the primary base class vtable, and which
2294 should therefore be appended to the end of the vtable for T. */
2296 static tree
2297 modify_all_vtables (tree t, tree virtuals)
2299 tree binfo = TYPE_BINFO (t);
2300 tree *fnsp;
2302 /* Update all of the vtables. */
2303 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2305 /* Add virtual functions not already in our primary vtable. These
2306 will be both those introduced by this class, and those overridden
2307 from secondary bases. It does not include virtuals merely
2308 inherited from secondary bases. */
2309 for (fnsp = &virtuals; *fnsp; )
2311 tree fn = TREE_VALUE (*fnsp);
2313 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2314 || DECL_VINDEX (fn) == error_mark_node)
2316 /* We don't need to adjust the `this' pointer when
2317 calling this function. */
2318 BV_DELTA (*fnsp) = integer_zero_node;
2319 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2321 /* This is a function not already in our vtable. Keep it. */
2322 fnsp = &TREE_CHAIN (*fnsp);
2324 else
2325 /* We've already got an entry for this function. Skip it. */
2326 *fnsp = TREE_CHAIN (*fnsp);
2329 return virtuals;
2332 /* Get the base virtual function declarations in T that have the
2333 indicated NAME. */
2335 static tree
2336 get_basefndecls (tree name, tree t)
2338 tree methods;
2339 tree base_fndecls = NULL_TREE;
2340 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2341 int i;
2343 /* Find virtual functions in T with the indicated NAME. */
2344 i = lookup_fnfields_1 (t, name);
2345 if (i != -1)
2346 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2347 methods;
2348 methods = OVL_NEXT (methods))
2350 tree method = OVL_CURRENT (methods);
2352 if (TREE_CODE (method) == FUNCTION_DECL
2353 && DECL_VINDEX (method))
2354 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2357 if (base_fndecls)
2358 return base_fndecls;
2360 for (i = 0; i < n_baseclasses; i++)
2362 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2363 base_fndecls = chainon (get_basefndecls (name, basetype),
2364 base_fndecls);
2367 return base_fndecls;
2370 /* If this declaration supersedes the declaration of
2371 a method declared virtual in the base class, then
2372 mark this field as being virtual as well. */
2374 void
2375 check_for_override (tree decl, tree ctype)
2377 if (TREE_CODE (decl) == TEMPLATE_DECL)
2378 /* In [temp.mem] we have:
2380 A specialization of a member function template does not
2381 override a virtual function from a base class. */
2382 return;
2383 if ((DECL_DESTRUCTOR_P (decl)
2384 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2385 || DECL_CONV_FN_P (decl))
2386 && look_for_overrides (ctype, decl)
2387 && !DECL_STATIC_FUNCTION_P (decl))
2388 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2389 the error_mark_node so that we know it is an overriding
2390 function. */
2391 DECL_VINDEX (decl) = decl;
2393 if (DECL_VIRTUAL_P (decl))
2395 if (!DECL_VINDEX (decl))
2396 DECL_VINDEX (decl) = error_mark_node;
2397 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2401 /* Warn about hidden virtual functions that are not overridden in t.
2402 We know that constructors and destructors don't apply. */
2404 static void
2405 warn_hidden (tree t)
2407 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2408 tree fns;
2409 size_t i;
2411 /* We go through each separately named virtual function. */
2412 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2413 VEC_iterate (tree, method_vec, i, fns);
2414 ++i)
2416 tree fn;
2417 tree name;
2418 tree fndecl;
2419 tree base_fndecls;
2420 tree base_binfo;
2421 tree binfo;
2422 int j;
2424 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2425 have the same name. Figure out what name that is. */
2426 name = DECL_NAME (OVL_CURRENT (fns));
2427 /* There are no possibly hidden functions yet. */
2428 base_fndecls = NULL_TREE;
2429 /* Iterate through all of the base classes looking for possibly
2430 hidden functions. */
2431 for (binfo = TYPE_BINFO (t), j = 0;
2432 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2434 tree basetype = BINFO_TYPE (base_binfo);
2435 base_fndecls = chainon (get_basefndecls (name, basetype),
2436 base_fndecls);
2439 /* If there are no functions to hide, continue. */
2440 if (!base_fndecls)
2441 continue;
2443 /* Remove any overridden functions. */
2444 for (fn = fns; fn; fn = OVL_NEXT (fn))
2446 fndecl = OVL_CURRENT (fn);
2447 if (DECL_VINDEX (fndecl))
2449 tree *prev = &base_fndecls;
2451 while (*prev)
2452 /* If the method from the base class has the same
2453 signature as the method from the derived class, it
2454 has been overridden. */
2455 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2456 *prev = TREE_CHAIN (*prev);
2457 else
2458 prev = &TREE_CHAIN (*prev);
2462 /* Now give a warning for all base functions without overriders,
2463 as they are hidden. */
2464 while (base_fndecls)
2466 /* Here we know it is a hider, and no overrider exists. */
2467 warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls));
2468 warning (OPT_Woverloaded_virtual, " by %q+D", fns);
2469 base_fndecls = TREE_CHAIN (base_fndecls);
2474 /* Check for things that are invalid. There are probably plenty of other
2475 things we should check for also. */
2477 static void
2478 finish_struct_anon (tree t)
2480 tree field;
2482 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2484 if (TREE_STATIC (field))
2485 continue;
2486 if (TREE_CODE (field) != FIELD_DECL)
2487 continue;
2489 if (DECL_NAME (field) == NULL_TREE
2490 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2492 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
2493 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2494 for (; elt; elt = TREE_CHAIN (elt))
2496 /* We're generally only interested in entities the user
2497 declared, but we also find nested classes by noticing
2498 the TYPE_DECL that we create implicitly. You're
2499 allowed to put one anonymous union inside another,
2500 though, so we explicitly tolerate that. We use
2501 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2502 we also allow unnamed types used for defining fields. */
2503 if (DECL_ARTIFICIAL (elt)
2504 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2505 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2506 continue;
2508 if (TREE_CODE (elt) != FIELD_DECL)
2510 if (is_union)
2511 permerror (input_location, "%q+#D invalid; an anonymous union can "
2512 "only have non-static data members", elt);
2513 else
2514 permerror (input_location, "%q+#D invalid; an anonymous struct can "
2515 "only have non-static data members", elt);
2516 continue;
2519 if (TREE_PRIVATE (elt))
2521 if (is_union)
2522 permerror (input_location, "private member %q+#D in anonymous union", elt);
2523 else
2524 permerror (input_location, "private member %q+#D in anonymous struct", elt);
2526 else if (TREE_PROTECTED (elt))
2528 if (is_union)
2529 permerror (input_location, "protected member %q+#D in anonymous union", elt);
2530 else
2531 permerror (input_location, "protected member %q+#D in anonymous struct", elt);
2534 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2535 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2541 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2542 will be used later during class template instantiation.
2543 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2544 a non-static member data (FIELD_DECL), a member function
2545 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2546 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2547 When FRIEND_P is nonzero, T is either a friend class
2548 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2549 (FUNCTION_DECL, TEMPLATE_DECL). */
2551 void
2552 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2554 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2555 if (CLASSTYPE_TEMPLATE_INFO (type))
2556 CLASSTYPE_DECL_LIST (type)
2557 = tree_cons (friend_p ? NULL_TREE : type,
2558 t, CLASSTYPE_DECL_LIST (type));
2561 /* Create default constructors, assignment operators, and so forth for
2562 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2563 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2564 the class cannot have a default constructor, copy constructor
2565 taking a const reference argument, or an assignment operator taking
2566 a const reference, respectively. */
2568 static void
2569 add_implicitly_declared_members (tree t,
2570 int cant_have_const_cctor,
2571 int cant_have_const_assignment)
2573 /* Destructor. */
2574 if (!CLASSTYPE_DESTRUCTORS (t))
2576 /* In general, we create destructors lazily. */
2577 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2578 /* However, if the implicit destructor is non-trivial
2579 destructor, we sometimes have to create it at this point. */
2580 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2582 bool lazy_p = true;
2584 if (TYPE_FOR_JAVA (t))
2585 /* If this a Java class, any non-trivial destructor is
2586 invalid, even if compiler-generated. Therefore, if the
2587 destructor is non-trivial we create it now. */
2588 lazy_p = false;
2589 else
2591 tree binfo;
2592 tree base_binfo;
2593 int ix;
2595 /* If the implicit destructor will be virtual, then we must
2596 generate it now because (unfortunately) we do not
2597 generate virtual tables lazily. */
2598 binfo = TYPE_BINFO (t);
2599 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2601 tree base_type;
2602 tree dtor;
2604 base_type = BINFO_TYPE (base_binfo);
2605 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2606 if (dtor && DECL_VIRTUAL_P (dtor))
2608 lazy_p = false;
2609 break;
2614 /* If we can't get away with being lazy, generate the destructor
2615 now. */
2616 if (!lazy_p)
2617 lazily_declare_fn (sfk_destructor, t);
2621 /* [class.ctor]
2623 If there is no user-declared constructor for a class, a default
2624 constructor is implicitly declared. */
2625 if (! TYPE_HAS_USER_CONSTRUCTOR (t))
2627 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2628 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2631 /* [class.ctor]
2633 If a class definition does not explicitly declare a copy
2634 constructor, one is declared implicitly. */
2635 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2637 TYPE_HAS_INIT_REF (t) = 1;
2638 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2639 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2642 /* If there is no assignment operator, one will be created if and
2643 when it is needed. For now, just record whether or not the type
2644 of the parameter to the assignment operator will be a const or
2645 non-const reference. */
2646 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2648 TYPE_HAS_ASSIGN_REF (t) = 1;
2649 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2650 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2654 /* Subroutine of finish_struct_1. Recursively count the number of fields
2655 in TYPE, including anonymous union members. */
2657 static int
2658 count_fields (tree fields)
2660 tree x;
2661 int n_fields = 0;
2662 for (x = fields; x; x = TREE_CHAIN (x))
2664 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2665 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2666 else
2667 n_fields += 1;
2669 return n_fields;
2672 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2673 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2675 static int
2676 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2678 tree x;
2679 for (x = fields; x; x = TREE_CHAIN (x))
2681 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2682 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2683 else
2684 field_vec->elts[idx++] = x;
2686 return idx;
2689 /* FIELD is a bit-field. We are finishing the processing for its
2690 enclosing type. Issue any appropriate messages and set appropriate
2691 flags. Returns false if an error has been diagnosed. */
2693 static bool
2694 check_bitfield_decl (tree field)
2696 tree type = TREE_TYPE (field);
2697 tree w;
2699 /* Extract the declared width of the bitfield, which has been
2700 temporarily stashed in DECL_INITIAL. */
2701 w = DECL_INITIAL (field);
2702 gcc_assert (w != NULL_TREE);
2703 /* Remove the bit-field width indicator so that the rest of the
2704 compiler does not treat that value as an initializer. */
2705 DECL_INITIAL (field) = NULL_TREE;
2707 /* Detect invalid bit-field type. */
2708 if (!INTEGRAL_TYPE_P (type))
2710 error ("bit-field %q+#D with non-integral type", field);
2711 w = error_mark_node;
2713 else
2715 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2716 STRIP_NOPS (w);
2718 /* detect invalid field size. */
2719 w = integral_constant_value (w);
2721 if (TREE_CODE (w) != INTEGER_CST)
2723 error ("bit-field %q+D width not an integer constant", field);
2724 w = error_mark_node;
2726 else if (tree_int_cst_sgn (w) < 0)
2728 error ("negative width in bit-field %q+D", field);
2729 w = error_mark_node;
2731 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2733 error ("zero width for bit-field %q+D", field);
2734 w = error_mark_node;
2736 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2737 && TREE_CODE (type) != ENUMERAL_TYPE
2738 && TREE_CODE (type) != BOOLEAN_TYPE)
2739 warning (0, "width of %q+D exceeds its type", field);
2740 else if (TREE_CODE (type) == ENUMERAL_TYPE
2741 && (0 > compare_tree_int (w,
2742 tree_int_cst_min_precision
2743 (TYPE_MIN_VALUE (type),
2744 TYPE_UNSIGNED (type)))
2745 || 0 > compare_tree_int (w,
2746 tree_int_cst_min_precision
2747 (TYPE_MAX_VALUE (type),
2748 TYPE_UNSIGNED (type)))))
2749 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2752 if (w != error_mark_node)
2754 DECL_SIZE (field) = convert (bitsizetype, w);
2755 DECL_BIT_FIELD (field) = 1;
2756 return true;
2758 else
2760 /* Non-bit-fields are aligned for their type. */
2761 DECL_BIT_FIELD (field) = 0;
2762 CLEAR_DECL_C_BIT_FIELD (field);
2763 return false;
2767 /* FIELD is a non bit-field. We are finishing the processing for its
2768 enclosing type T. Issue any appropriate messages and set appropriate
2769 flags. */
2771 static void
2772 check_field_decl (tree field,
2773 tree t,
2774 int* cant_have_const_ctor,
2775 int* no_const_asn_ref,
2776 int* any_default_members)
2778 tree type = strip_array_types (TREE_TYPE (field));
2780 /* An anonymous union cannot contain any fields which would change
2781 the settings of CANT_HAVE_CONST_CTOR and friends. */
2782 if (ANON_UNION_TYPE_P (type))
2784 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2785 structs. So, we recurse through their fields here. */
2786 else if (ANON_AGGR_TYPE_P (type))
2788 tree fields;
2790 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2791 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2792 check_field_decl (fields, t, cant_have_const_ctor,
2793 no_const_asn_ref, any_default_members);
2795 /* Check members with class type for constructors, destructors,
2796 etc. */
2797 else if (CLASS_TYPE_P (type))
2799 /* Never let anything with uninheritable virtuals
2800 make it through without complaint. */
2801 abstract_virtuals_error (field, type);
2803 if (TREE_CODE (t) == UNION_TYPE)
2805 if (TYPE_NEEDS_CONSTRUCTING (type))
2806 error ("member %q+#D with constructor not allowed in union",
2807 field);
2808 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2809 error ("member %q+#D with destructor not allowed in union", field);
2810 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2811 error ("member %q+#D with copy assignment operator not allowed in union",
2812 field);
2814 else
2816 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2817 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2818 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2819 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2820 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2821 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (type);
2824 if (!TYPE_HAS_CONST_INIT_REF (type))
2825 *cant_have_const_ctor = 1;
2827 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2828 *no_const_asn_ref = 1;
2830 if (DECL_INITIAL (field) != NULL_TREE)
2832 /* `build_class_init_list' does not recognize
2833 non-FIELD_DECLs. */
2834 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2835 error ("multiple fields in union %qT initialized", t);
2836 *any_default_members = 1;
2840 /* Check the data members (both static and non-static), class-scoped
2841 typedefs, etc., appearing in the declaration of T. Issue
2842 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2843 declaration order) of access declarations; each TREE_VALUE in this
2844 list is a USING_DECL.
2846 In addition, set the following flags:
2848 EMPTY_P
2849 The class is empty, i.e., contains no non-static data members.
2851 CANT_HAVE_CONST_CTOR_P
2852 This class cannot have an implicitly generated copy constructor
2853 taking a const reference.
2855 CANT_HAVE_CONST_ASN_REF
2856 This class cannot have an implicitly generated assignment
2857 operator taking a const reference.
2859 All of these flags should be initialized before calling this
2860 function.
2862 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2863 fields can be added by adding to this chain. */
2865 static void
2866 check_field_decls (tree t, tree *access_decls,
2867 int *cant_have_const_ctor_p,
2868 int *no_const_asn_ref_p)
2870 tree *field;
2871 tree *next;
2872 bool has_pointers;
2873 int any_default_members;
2874 int cant_pack = 0;
2876 /* Assume there are no access declarations. */
2877 *access_decls = NULL_TREE;
2878 /* Assume this class has no pointer members. */
2879 has_pointers = false;
2880 /* Assume none of the members of this class have default
2881 initializations. */
2882 any_default_members = 0;
2884 for (field = &TYPE_FIELDS (t); *field; field = next)
2886 tree x = *field;
2887 tree type = TREE_TYPE (x);
2889 next = &TREE_CHAIN (x);
2891 if (TREE_CODE (x) == USING_DECL)
2893 /* Prune the access declaration from the list of fields. */
2894 *field = TREE_CHAIN (x);
2896 /* Save the access declarations for our caller. */
2897 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2899 /* Since we've reset *FIELD there's no reason to skip to the
2900 next field. */
2901 next = field;
2902 continue;
2905 if (TREE_CODE (x) == TYPE_DECL
2906 || TREE_CODE (x) == TEMPLATE_DECL)
2907 continue;
2909 /* If we've gotten this far, it's a data member, possibly static,
2910 or an enumerator. */
2911 DECL_CONTEXT (x) = t;
2913 /* When this goes into scope, it will be a non-local reference. */
2914 DECL_NONLOCAL (x) = 1;
2916 if (TREE_CODE (t) == UNION_TYPE)
2918 /* [class.union]
2920 If a union contains a static data member, or a member of
2921 reference type, the program is ill-formed. */
2922 if (TREE_CODE (x) == VAR_DECL)
2924 error ("%q+D may not be static because it is a member of a union", x);
2925 continue;
2927 if (TREE_CODE (type) == REFERENCE_TYPE)
2929 error ("%q+D may not have reference type %qT because"
2930 " it is a member of a union",
2931 x, type);
2932 continue;
2936 /* Perform error checking that did not get done in
2937 grokdeclarator. */
2938 if (TREE_CODE (type) == FUNCTION_TYPE)
2940 error ("field %q+D invalidly declared function type", x);
2941 type = build_pointer_type (type);
2942 TREE_TYPE (x) = type;
2944 else if (TREE_CODE (type) == METHOD_TYPE)
2946 error ("field %q+D invalidly declared method type", x);
2947 type = build_pointer_type (type);
2948 TREE_TYPE (x) = type;
2951 if (type == error_mark_node)
2952 continue;
2954 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2955 continue;
2957 /* Now it can only be a FIELD_DECL. */
2959 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2960 CLASSTYPE_NON_AGGREGATE (t) = 1;
2962 /* If this is of reference type, check if it needs an init. */
2963 if (TREE_CODE (type) == REFERENCE_TYPE)
2965 CLASSTYPE_NON_POD_P (t) = 1;
2966 if (DECL_INITIAL (x) == NULL_TREE)
2967 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2969 /* ARM $12.6.2: [A member initializer list] (or, for an
2970 aggregate, initialization by a brace-enclosed list) is the
2971 only way to initialize nonstatic const and reference
2972 members. */
2973 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2976 type = strip_array_types (type);
2978 if (TYPE_PACKED (t))
2980 if (!pod_type_p (type) && !TYPE_PACKED (type))
2982 warning
2984 "ignoring packed attribute because of unpacked non-POD field %q+#D",
2986 cant_pack = 1;
2988 else if (DECL_C_BIT_FIELD (x)
2989 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
2990 DECL_PACKED (x) = 1;
2993 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2994 /* We don't treat zero-width bitfields as making a class
2995 non-empty. */
2997 else
2999 /* The class is non-empty. */
3000 CLASSTYPE_EMPTY_P (t) = 0;
3001 /* The class is not even nearly empty. */
3002 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3003 /* If one of the data members contains an empty class,
3004 so does T. */
3005 if (CLASS_TYPE_P (type)
3006 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3007 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
3010 /* This is used by -Weffc++ (see below). Warn only for pointers
3011 to members which might hold dynamic memory. So do not warn
3012 for pointers to functions or pointers to members. */
3013 if (TYPE_PTR_P (type)
3014 && !TYPE_PTRFN_P (type)
3015 && !TYPE_PTR_TO_MEMBER_P (type))
3016 has_pointers = true;
3018 if (CLASS_TYPE_P (type))
3020 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3021 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3022 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3023 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3026 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3027 CLASSTYPE_HAS_MUTABLE (t) = 1;
3029 if (! pod_type_p (type))
3030 /* DR 148 now allows pointers to members (which are POD themselves),
3031 to be allowed in POD structs. */
3032 CLASSTYPE_NON_POD_P (t) = 1;
3034 if (! zero_init_p (type))
3035 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3037 /* If any field is const, the structure type is pseudo-const. */
3038 if (CP_TYPE_CONST_P (type))
3040 C_TYPE_FIELDS_READONLY (t) = 1;
3041 if (DECL_INITIAL (x) == NULL_TREE)
3042 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3044 /* ARM $12.6.2: [A member initializer list] (or, for an
3045 aggregate, initialization by a brace-enclosed list) is the
3046 only way to initialize nonstatic const and reference
3047 members. */
3048 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3050 /* A field that is pseudo-const makes the structure likewise. */
3051 else if (CLASS_TYPE_P (type))
3053 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3054 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3055 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3056 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3059 /* Core issue 80: A nonstatic data member is required to have a
3060 different name from the class iff the class has a
3061 user-declared constructor. */
3062 if (constructor_name_p (DECL_NAME (x), t)
3063 && TYPE_HAS_USER_CONSTRUCTOR (t))
3064 permerror (input_location, "field %q+#D with same name as class", x);
3066 /* We set DECL_C_BIT_FIELD in grokbitfield.
3067 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3068 if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x))
3069 check_field_decl (x, t,
3070 cant_have_const_ctor_p,
3071 no_const_asn_ref_p,
3072 &any_default_members);
3075 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3076 it should also define a copy constructor and an assignment operator to
3077 implement the correct copy semantic (deep vs shallow, etc.). As it is
3078 not feasible to check whether the constructors do allocate dynamic memory
3079 and store it within members, we approximate the warning like this:
3081 -- Warn only if there are members which are pointers
3082 -- Warn only if there is a non-trivial constructor (otherwise,
3083 there cannot be memory allocated).
3084 -- Warn only if there is a non-trivial destructor. We assume that the
3085 user at least implemented the cleanup correctly, and a destructor
3086 is needed to free dynamic memory.
3088 This seems enough for practical purposes. */
3089 if (warn_ecpp
3090 && has_pointers
3091 && TYPE_HAS_USER_CONSTRUCTOR (t)
3092 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3093 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3095 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3097 if (! TYPE_HAS_INIT_REF (t))
3099 warning (OPT_Weffc__,
3100 " but does not override %<%T(const %T&)%>", t, t);
3101 if (!TYPE_HAS_ASSIGN_REF (t))
3102 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3104 else if (! TYPE_HAS_ASSIGN_REF (t))
3105 warning (OPT_Weffc__,
3106 " but does not override %<operator=(const %T&)%>", t);
3109 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3110 if (cant_pack)
3111 TYPE_PACKED (t) = 0;
3113 /* Check anonymous struct/anonymous union fields. */
3114 finish_struct_anon (t);
3116 /* We've built up the list of access declarations in reverse order.
3117 Fix that now. */
3118 *access_decls = nreverse (*access_decls);
3121 /* If TYPE is an empty class type, records its OFFSET in the table of
3122 OFFSETS. */
3124 static int
3125 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3127 splay_tree_node n;
3129 if (!is_empty_class (type))
3130 return 0;
3132 /* Record the location of this empty object in OFFSETS. */
3133 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3134 if (!n)
3135 n = splay_tree_insert (offsets,
3136 (splay_tree_key) offset,
3137 (splay_tree_value) NULL_TREE);
3138 n->value = ((splay_tree_value)
3139 tree_cons (NULL_TREE,
3140 type,
3141 (tree) n->value));
3143 return 0;
3146 /* Returns nonzero if TYPE is an empty class type and there is
3147 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3149 static int
3150 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3152 splay_tree_node n;
3153 tree t;
3155 if (!is_empty_class (type))
3156 return 0;
3158 /* Record the location of this empty object in OFFSETS. */
3159 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3160 if (!n)
3161 return 0;
3163 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3164 if (same_type_p (TREE_VALUE (t), type))
3165 return 1;
3167 return 0;
3170 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3171 F for every subobject, passing it the type, offset, and table of
3172 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3173 be traversed.
3175 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3176 than MAX_OFFSET will not be walked.
3178 If F returns a nonzero value, the traversal ceases, and that value
3179 is returned. Otherwise, returns zero. */
3181 static int
3182 walk_subobject_offsets (tree type,
3183 subobject_offset_fn f,
3184 tree offset,
3185 splay_tree offsets,
3186 tree max_offset,
3187 int vbases_p)
3189 int r = 0;
3190 tree type_binfo = NULL_TREE;
3192 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3193 stop. */
3194 if (max_offset && INT_CST_LT (max_offset, offset))
3195 return 0;
3197 if (type == error_mark_node)
3198 return 0;
3200 if (!TYPE_P (type))
3202 if (abi_version_at_least (2))
3203 type_binfo = type;
3204 type = BINFO_TYPE (type);
3207 if (CLASS_TYPE_P (type))
3209 tree field;
3210 tree binfo;
3211 int i;
3213 /* Avoid recursing into objects that are not interesting. */
3214 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3215 return 0;
3217 /* Record the location of TYPE. */
3218 r = (*f) (type, offset, offsets);
3219 if (r)
3220 return r;
3222 /* Iterate through the direct base classes of TYPE. */
3223 if (!type_binfo)
3224 type_binfo = TYPE_BINFO (type);
3225 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3227 tree binfo_offset;
3229 if (abi_version_at_least (2)
3230 && BINFO_VIRTUAL_P (binfo))
3231 continue;
3233 if (!vbases_p
3234 && BINFO_VIRTUAL_P (binfo)
3235 && !BINFO_PRIMARY_P (binfo))
3236 continue;
3238 if (!abi_version_at_least (2))
3239 binfo_offset = size_binop (PLUS_EXPR,
3240 offset,
3241 BINFO_OFFSET (binfo));
3242 else
3244 tree orig_binfo;
3245 /* We cannot rely on BINFO_OFFSET being set for the base
3246 class yet, but the offsets for direct non-virtual
3247 bases can be calculated by going back to the TYPE. */
3248 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3249 binfo_offset = size_binop (PLUS_EXPR,
3250 offset,
3251 BINFO_OFFSET (orig_binfo));
3254 r = walk_subobject_offsets (binfo,
3256 binfo_offset,
3257 offsets,
3258 max_offset,
3259 (abi_version_at_least (2)
3260 ? /*vbases_p=*/0 : vbases_p));
3261 if (r)
3262 return r;
3265 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3267 unsigned ix;
3268 VEC(tree,gc) *vbases;
3270 /* Iterate through the virtual base classes of TYPE. In G++
3271 3.2, we included virtual bases in the direct base class
3272 loop above, which results in incorrect results; the
3273 correct offsets for virtual bases are only known when
3274 working with the most derived type. */
3275 if (vbases_p)
3276 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3277 VEC_iterate (tree, vbases, ix, binfo); ix++)
3279 r = walk_subobject_offsets (binfo,
3281 size_binop (PLUS_EXPR,
3282 offset,
3283 BINFO_OFFSET (binfo)),
3284 offsets,
3285 max_offset,
3286 /*vbases_p=*/0);
3287 if (r)
3288 return r;
3290 else
3292 /* We still have to walk the primary base, if it is
3293 virtual. (If it is non-virtual, then it was walked
3294 above.) */
3295 tree vbase = get_primary_binfo (type_binfo);
3297 if (vbase && BINFO_VIRTUAL_P (vbase)
3298 && BINFO_PRIMARY_P (vbase)
3299 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3301 r = (walk_subobject_offsets
3302 (vbase, f, offset,
3303 offsets, max_offset, /*vbases_p=*/0));
3304 if (r)
3305 return r;
3310 /* Iterate through the fields of TYPE. */
3311 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3312 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3314 tree field_offset;
3316 if (abi_version_at_least (2))
3317 field_offset = byte_position (field);
3318 else
3319 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3320 field_offset = DECL_FIELD_OFFSET (field);
3322 r = walk_subobject_offsets (TREE_TYPE (field),
3324 size_binop (PLUS_EXPR,
3325 offset,
3326 field_offset),
3327 offsets,
3328 max_offset,
3329 /*vbases_p=*/1);
3330 if (r)
3331 return r;
3334 else if (TREE_CODE (type) == ARRAY_TYPE)
3336 tree element_type = strip_array_types (type);
3337 tree domain = TYPE_DOMAIN (type);
3338 tree index;
3340 /* Avoid recursing into objects that are not interesting. */
3341 if (!CLASS_TYPE_P (element_type)
3342 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3343 return 0;
3345 /* Step through each of the elements in the array. */
3346 for (index = size_zero_node;
3347 /* G++ 3.2 had an off-by-one error here. */
3348 (abi_version_at_least (2)
3349 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3350 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3351 index = size_binop (PLUS_EXPR, index, size_one_node))
3353 r = walk_subobject_offsets (TREE_TYPE (type),
3355 offset,
3356 offsets,
3357 max_offset,
3358 /*vbases_p=*/1);
3359 if (r)
3360 return r;
3361 offset = size_binop (PLUS_EXPR, offset,
3362 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3363 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3364 there's no point in iterating through the remaining
3365 elements of the array. */
3366 if (max_offset && INT_CST_LT (max_offset, offset))
3367 break;
3371 return 0;
3374 /* Record all of the empty subobjects of TYPE (either a type or a
3375 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3376 is being placed at OFFSET; otherwise, it is a base class that is
3377 being placed at OFFSET. */
3379 static void
3380 record_subobject_offsets (tree type,
3381 tree offset,
3382 splay_tree offsets,
3383 bool is_data_member)
3385 tree max_offset;
3386 /* If recording subobjects for a non-static data member or a
3387 non-empty base class , we do not need to record offsets beyond
3388 the size of the biggest empty class. Additional data members
3389 will go at the end of the class. Additional base classes will go
3390 either at offset zero (if empty, in which case they cannot
3391 overlap with offsets past the size of the biggest empty class) or
3392 at the end of the class.
3394 However, if we are placing an empty base class, then we must record
3395 all offsets, as either the empty class is at offset zero (where
3396 other empty classes might later be placed) or at the end of the
3397 class (where other objects might then be placed, so other empty
3398 subobjects might later overlap). */
3399 if (is_data_member
3400 || !is_empty_class (BINFO_TYPE (type)))
3401 max_offset = sizeof_biggest_empty_class;
3402 else
3403 max_offset = NULL_TREE;
3404 walk_subobject_offsets (type, record_subobject_offset, offset,
3405 offsets, max_offset, is_data_member);
3408 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3409 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3410 virtual bases of TYPE are examined. */
3412 static int
3413 layout_conflict_p (tree type,
3414 tree offset,
3415 splay_tree offsets,
3416 int vbases_p)
3418 splay_tree_node max_node;
3420 /* Get the node in OFFSETS that indicates the maximum offset where
3421 an empty subobject is located. */
3422 max_node = splay_tree_max (offsets);
3423 /* If there aren't any empty subobjects, then there's no point in
3424 performing this check. */
3425 if (!max_node)
3426 return 0;
3428 return walk_subobject_offsets (type, check_subobject_offset, offset,
3429 offsets, (tree) (max_node->key),
3430 vbases_p);
3433 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3434 non-static data member of the type indicated by RLI. BINFO is the
3435 binfo corresponding to the base subobject, OFFSETS maps offsets to
3436 types already located at those offsets. This function determines
3437 the position of the DECL. */
3439 static void
3440 layout_nonempty_base_or_field (record_layout_info rli,
3441 tree decl,
3442 tree binfo,
3443 splay_tree offsets)
3445 tree offset = NULL_TREE;
3446 bool field_p;
3447 tree type;
3449 if (binfo)
3451 /* For the purposes of determining layout conflicts, we want to
3452 use the class type of BINFO; TREE_TYPE (DECL) will be the
3453 CLASSTYPE_AS_BASE version, which does not contain entries for
3454 zero-sized bases. */
3455 type = TREE_TYPE (binfo);
3456 field_p = false;
3458 else
3460 type = TREE_TYPE (decl);
3461 field_p = true;
3464 /* Try to place the field. It may take more than one try if we have
3465 a hard time placing the field without putting two objects of the
3466 same type at the same address. */
3467 while (1)
3469 struct record_layout_info_s old_rli = *rli;
3471 /* Place this field. */
3472 place_field (rli, decl);
3473 offset = byte_position (decl);
3475 /* We have to check to see whether or not there is already
3476 something of the same type at the offset we're about to use.
3477 For example, consider:
3479 struct S {};
3480 struct T : public S { int i; };
3481 struct U : public S, public T {};
3483 Here, we put S at offset zero in U. Then, we can't put T at
3484 offset zero -- its S component would be at the same address
3485 as the S we already allocated. So, we have to skip ahead.
3486 Since all data members, including those whose type is an
3487 empty class, have nonzero size, any overlap can happen only
3488 with a direct or indirect base-class -- it can't happen with
3489 a data member. */
3490 /* In a union, overlap is permitted; all members are placed at
3491 offset zero. */
3492 if (TREE_CODE (rli->t) == UNION_TYPE)
3493 break;
3494 /* G++ 3.2 did not check for overlaps when placing a non-empty
3495 virtual base. */
3496 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3497 break;
3498 if (layout_conflict_p (field_p ? type : binfo, offset,
3499 offsets, field_p))
3501 /* Strip off the size allocated to this field. That puts us
3502 at the first place we could have put the field with
3503 proper alignment. */
3504 *rli = old_rli;
3506 /* Bump up by the alignment required for the type. */
3507 rli->bitpos
3508 = size_binop (PLUS_EXPR, rli->bitpos,
3509 bitsize_int (binfo
3510 ? CLASSTYPE_ALIGN (type)
3511 : TYPE_ALIGN (type)));
3512 normalize_rli (rli);
3514 else
3515 /* There was no conflict. We're done laying out this field. */
3516 break;
3519 /* Now that we know where it will be placed, update its
3520 BINFO_OFFSET. */
3521 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3522 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3523 this point because their BINFO_OFFSET is copied from another
3524 hierarchy. Therefore, we may not need to add the entire
3525 OFFSET. */
3526 propagate_binfo_offsets (binfo,
3527 size_diffop (convert (ssizetype, offset),
3528 convert (ssizetype,
3529 BINFO_OFFSET (binfo))));
3532 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3534 static int
3535 empty_base_at_nonzero_offset_p (tree type,
3536 tree offset,
3537 splay_tree offsets ATTRIBUTE_UNUSED)
3539 return is_empty_class (type) && !integer_zerop (offset);
3542 /* Layout the empty base BINFO. EOC indicates the byte currently just
3543 past the end of the class, and should be correctly aligned for a
3544 class of the type indicated by BINFO; OFFSETS gives the offsets of
3545 the empty bases allocated so far. T is the most derived
3546 type. Return nonzero iff we added it at the end. */
3548 static bool
3549 layout_empty_base (record_layout_info rli, tree binfo,
3550 tree eoc, splay_tree offsets)
3552 tree alignment;
3553 tree basetype = BINFO_TYPE (binfo);
3554 bool atend = false;
3556 /* This routine should only be used for empty classes. */
3557 gcc_assert (is_empty_class (basetype));
3558 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3560 if (!integer_zerop (BINFO_OFFSET (binfo)))
3562 if (abi_version_at_least (2))
3563 propagate_binfo_offsets
3564 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3565 else
3566 warning (OPT_Wabi,
3567 "offset of empty base %qT may not be ABI-compliant and may"
3568 "change in a future version of GCC",
3569 BINFO_TYPE (binfo));
3572 /* This is an empty base class. We first try to put it at offset
3573 zero. */
3574 if (layout_conflict_p (binfo,
3575 BINFO_OFFSET (binfo),
3576 offsets,
3577 /*vbases_p=*/0))
3579 /* That didn't work. Now, we move forward from the next
3580 available spot in the class. */
3581 atend = true;
3582 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3583 while (1)
3585 if (!layout_conflict_p (binfo,
3586 BINFO_OFFSET (binfo),
3587 offsets,
3588 /*vbases_p=*/0))
3589 /* We finally found a spot where there's no overlap. */
3590 break;
3592 /* There's overlap here, too. Bump along to the next spot. */
3593 propagate_binfo_offsets (binfo, alignment);
3597 if (CLASSTYPE_USER_ALIGN (basetype))
3599 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype));
3600 if (warn_packed)
3601 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype));
3602 TYPE_USER_ALIGN (rli->t) = 1;
3605 return atend;
3608 /* Layout the base given by BINFO in the class indicated by RLI.
3609 *BASE_ALIGN is a running maximum of the alignments of
3610 any base class. OFFSETS gives the location of empty base
3611 subobjects. T is the most derived type. Return nonzero if the new
3612 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3613 *NEXT_FIELD, unless BINFO is for an empty base class.
3615 Returns the location at which the next field should be inserted. */
3617 static tree *
3618 build_base_field (record_layout_info rli, tree binfo,
3619 splay_tree offsets, tree *next_field)
3621 tree t = rli->t;
3622 tree basetype = BINFO_TYPE (binfo);
3624 if (!COMPLETE_TYPE_P (basetype))
3625 /* This error is now reported in xref_tag, thus giving better
3626 location information. */
3627 return next_field;
3629 /* Place the base class. */
3630 if (!is_empty_class (basetype))
3632 tree decl;
3634 /* The containing class is non-empty because it has a non-empty
3635 base class. */
3636 CLASSTYPE_EMPTY_P (t) = 0;
3638 /* Create the FIELD_DECL. */
3639 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3640 DECL_ARTIFICIAL (decl) = 1;
3641 DECL_IGNORED_P (decl) = 1;
3642 DECL_FIELD_CONTEXT (decl) = t;
3643 if (CLASSTYPE_AS_BASE (basetype))
3645 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3646 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3647 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3648 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3649 DECL_MODE (decl) = TYPE_MODE (basetype);
3650 DECL_FIELD_IS_BASE (decl) = 1;
3652 /* Try to place the field. It may take more than one try if we
3653 have a hard time placing the field without putting two
3654 objects of the same type at the same address. */
3655 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3656 /* Add the new FIELD_DECL to the list of fields for T. */
3657 TREE_CHAIN (decl) = *next_field;
3658 *next_field = decl;
3659 next_field = &TREE_CHAIN (decl);
3662 else
3664 tree eoc;
3665 bool atend;
3667 /* On some platforms (ARM), even empty classes will not be
3668 byte-aligned. */
3669 eoc = round_up (rli_size_unit_so_far (rli),
3670 CLASSTYPE_ALIGN_UNIT (basetype));
3671 atend = layout_empty_base (rli, binfo, eoc, offsets);
3672 /* A nearly-empty class "has no proper base class that is empty,
3673 not morally virtual, and at an offset other than zero." */
3674 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3676 if (atend)
3677 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3678 /* The check above (used in G++ 3.2) is insufficient because
3679 an empty class placed at offset zero might itself have an
3680 empty base at a nonzero offset. */
3681 else if (walk_subobject_offsets (basetype,
3682 empty_base_at_nonzero_offset_p,
3683 size_zero_node,
3684 /*offsets=*/NULL,
3685 /*max_offset=*/NULL_TREE,
3686 /*vbases_p=*/true))
3688 if (abi_version_at_least (2))
3689 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3690 else
3691 warning (OPT_Wabi,
3692 "class %qT will be considered nearly empty in a "
3693 "future version of GCC", t);
3697 /* We do not create a FIELD_DECL for empty base classes because
3698 it might overlap some other field. We want to be able to
3699 create CONSTRUCTORs for the class by iterating over the
3700 FIELD_DECLs, and the back end does not handle overlapping
3701 FIELD_DECLs. */
3703 /* An empty virtual base causes a class to be non-empty
3704 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3705 here because that was already done when the virtual table
3706 pointer was created. */
3709 /* Record the offsets of BINFO and its base subobjects. */
3710 record_subobject_offsets (binfo,
3711 BINFO_OFFSET (binfo),
3712 offsets,
3713 /*is_data_member=*/false);
3715 return next_field;
3718 /* Layout all of the non-virtual base classes. Record empty
3719 subobjects in OFFSETS. T is the most derived type. Return nonzero
3720 if the type cannot be nearly empty. The fields created
3721 corresponding to the base classes will be inserted at
3722 *NEXT_FIELD. */
3724 static void
3725 build_base_fields (record_layout_info rli,
3726 splay_tree offsets, tree *next_field)
3728 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3729 subobjects. */
3730 tree t = rli->t;
3731 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3732 int i;
3734 /* The primary base class is always allocated first. */
3735 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3736 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3737 offsets, next_field);
3739 /* Now allocate the rest of the bases. */
3740 for (i = 0; i < n_baseclasses; ++i)
3742 tree base_binfo;
3744 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3746 /* The primary base was already allocated above, so we don't
3747 need to allocate it again here. */
3748 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3749 continue;
3751 /* Virtual bases are added at the end (a primary virtual base
3752 will have already been added). */
3753 if (BINFO_VIRTUAL_P (base_binfo))
3754 continue;
3756 next_field = build_base_field (rli, base_binfo,
3757 offsets, next_field);
3761 /* Go through the TYPE_METHODS of T issuing any appropriate
3762 diagnostics, figuring out which methods override which other
3763 methods, and so forth. */
3765 static void
3766 check_methods (tree t)
3768 tree x;
3770 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3772 check_for_override (x, t);
3773 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3774 error ("initializer specified for non-virtual method %q+D", x);
3775 /* The name of the field is the original field name
3776 Save this in auxiliary field for later overloading. */
3777 if (DECL_VINDEX (x))
3779 TYPE_POLYMORPHIC_P (t) = 1;
3780 if (DECL_PURE_VIRTUAL_P (x))
3781 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3783 /* All user-provided destructors are non-trivial. */
3784 if (DECL_DESTRUCTOR_P (x) && !DECL_DEFAULTED_FN (x))
3785 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3789 /* FN is a constructor or destructor. Clone the declaration to create
3790 a specialized in-charge or not-in-charge version, as indicated by
3791 NAME. */
3793 static tree
3794 build_clone (tree fn, tree name)
3796 tree parms;
3797 tree clone;
3799 /* Copy the function. */
3800 clone = copy_decl (fn);
3801 /* Remember where this function came from. */
3802 DECL_CLONED_FUNCTION (clone) = fn;
3803 DECL_ABSTRACT_ORIGIN (clone) = fn;
3804 /* Reset the function name. */
3805 DECL_NAME (clone) = name;
3806 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3807 /* There's no pending inline data for this function. */
3808 DECL_PENDING_INLINE_INFO (clone) = NULL;
3809 DECL_PENDING_INLINE_P (clone) = 0;
3810 /* And it hasn't yet been deferred. */
3811 DECL_DEFERRED_FN (clone) = 0;
3813 /* The base-class destructor is not virtual. */
3814 if (name == base_dtor_identifier)
3816 DECL_VIRTUAL_P (clone) = 0;
3817 if (TREE_CODE (clone) != TEMPLATE_DECL)
3818 DECL_VINDEX (clone) = NULL_TREE;
3821 /* If there was an in-charge parameter, drop it from the function
3822 type. */
3823 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3825 tree basetype;
3826 tree parmtypes;
3827 tree exceptions;
3829 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3830 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3831 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3832 /* Skip the `this' parameter. */
3833 parmtypes = TREE_CHAIN (parmtypes);
3834 /* Skip the in-charge parameter. */
3835 parmtypes = TREE_CHAIN (parmtypes);
3836 /* And the VTT parm, in a complete [cd]tor. */
3837 if (DECL_HAS_VTT_PARM_P (fn)
3838 && ! DECL_NEEDS_VTT_PARM_P (clone))
3839 parmtypes = TREE_CHAIN (parmtypes);
3840 /* If this is subobject constructor or destructor, add the vtt
3841 parameter. */
3842 TREE_TYPE (clone)
3843 = build_method_type_directly (basetype,
3844 TREE_TYPE (TREE_TYPE (clone)),
3845 parmtypes);
3846 if (exceptions)
3847 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3848 exceptions);
3849 TREE_TYPE (clone)
3850 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3851 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3854 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3855 aren't function parameters; those are the template parameters. */
3856 if (TREE_CODE (clone) != TEMPLATE_DECL)
3858 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3859 /* Remove the in-charge parameter. */
3860 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3862 TREE_CHAIN (DECL_ARGUMENTS (clone))
3863 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3864 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3866 /* And the VTT parm, in a complete [cd]tor. */
3867 if (DECL_HAS_VTT_PARM_P (fn))
3869 if (DECL_NEEDS_VTT_PARM_P (clone))
3870 DECL_HAS_VTT_PARM_P (clone) = 1;
3871 else
3873 TREE_CHAIN (DECL_ARGUMENTS (clone))
3874 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3875 DECL_HAS_VTT_PARM_P (clone) = 0;
3879 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3881 DECL_CONTEXT (parms) = clone;
3882 cxx_dup_lang_specific_decl (parms);
3886 /* Create the RTL for this function. */
3887 SET_DECL_RTL (clone, NULL_RTX);
3888 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3890 /* Make it easy to find the CLONE given the FN. */
3891 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3892 TREE_CHAIN (fn) = clone;
3894 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3895 if (TREE_CODE (clone) == TEMPLATE_DECL)
3897 tree result;
3899 DECL_TEMPLATE_RESULT (clone)
3900 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3901 result = DECL_TEMPLATE_RESULT (clone);
3902 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3903 DECL_TI_TEMPLATE (result) = clone;
3905 else if (pch_file)
3906 note_decl_for_pch (clone);
3908 return clone;
3911 /* Produce declarations for all appropriate clones of FN. If
3912 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3913 CLASTYPE_METHOD_VEC as well. */
3915 void
3916 clone_function_decl (tree fn, int update_method_vec_p)
3918 tree clone;
3920 /* Avoid inappropriate cloning. */
3921 if (TREE_CHAIN (fn)
3922 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3923 return;
3925 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3927 /* For each constructor, we need two variants: an in-charge version
3928 and a not-in-charge version. */
3929 clone = build_clone (fn, complete_ctor_identifier);
3930 if (update_method_vec_p)
3931 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3932 clone = build_clone (fn, base_ctor_identifier);
3933 if (update_method_vec_p)
3934 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3936 else
3938 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3940 /* For each destructor, we need three variants: an in-charge
3941 version, a not-in-charge version, and an in-charge deleting
3942 version. We clone the deleting version first because that
3943 means it will go second on the TYPE_METHODS list -- and that
3944 corresponds to the correct layout order in the virtual
3945 function table.
3947 For a non-virtual destructor, we do not build a deleting
3948 destructor. */
3949 if (DECL_VIRTUAL_P (fn))
3951 clone = build_clone (fn, deleting_dtor_identifier);
3952 if (update_method_vec_p)
3953 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3955 clone = build_clone (fn, complete_dtor_identifier);
3956 if (update_method_vec_p)
3957 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3958 clone = build_clone (fn, base_dtor_identifier);
3959 if (update_method_vec_p)
3960 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3963 /* Note that this is an abstract function that is never emitted. */
3964 DECL_ABSTRACT (fn) = 1;
3967 /* DECL is an in charge constructor, which is being defined. This will
3968 have had an in class declaration, from whence clones were
3969 declared. An out-of-class definition can specify additional default
3970 arguments. As it is the clones that are involved in overload
3971 resolution, we must propagate the information from the DECL to its
3972 clones. */
3974 void
3975 adjust_clone_args (tree decl)
3977 tree clone;
3979 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3980 clone = TREE_CHAIN (clone))
3982 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3983 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3984 tree decl_parms, clone_parms;
3986 clone_parms = orig_clone_parms;
3988 /* Skip the 'this' parameter. */
3989 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3990 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3992 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3993 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3994 if (DECL_HAS_VTT_PARM_P (decl))
3995 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3997 clone_parms = orig_clone_parms;
3998 if (DECL_HAS_VTT_PARM_P (clone))
3999 clone_parms = TREE_CHAIN (clone_parms);
4001 for (decl_parms = orig_decl_parms; decl_parms;
4002 decl_parms = TREE_CHAIN (decl_parms),
4003 clone_parms = TREE_CHAIN (clone_parms))
4005 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
4006 TREE_TYPE (clone_parms)));
4008 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
4010 /* A default parameter has been added. Adjust the
4011 clone's parameters. */
4012 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4013 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4014 tree type;
4016 clone_parms = orig_decl_parms;
4018 if (DECL_HAS_VTT_PARM_P (clone))
4020 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
4021 TREE_VALUE (orig_clone_parms),
4022 clone_parms);
4023 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
4025 type = build_method_type_directly (basetype,
4026 TREE_TYPE (TREE_TYPE (clone)),
4027 clone_parms);
4028 if (exceptions)
4029 type = build_exception_variant (type, exceptions);
4030 TREE_TYPE (clone) = type;
4032 clone_parms = NULL_TREE;
4033 break;
4036 gcc_assert (!clone_parms);
4040 /* For each of the constructors and destructors in T, create an
4041 in-charge and not-in-charge variant. */
4043 static void
4044 clone_constructors_and_destructors (tree t)
4046 tree fns;
4048 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4049 out now. */
4050 if (!CLASSTYPE_METHOD_VEC (t))
4051 return;
4053 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4054 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4055 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4056 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4059 /* Returns true iff class T has a user-defined constructor other than
4060 the default constructor. */
4062 bool
4063 type_has_user_nondefault_constructor (tree t)
4065 tree fns;
4067 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4068 return false;
4070 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4072 tree fn = OVL_CURRENT (fns);
4073 if (!DECL_ARTIFICIAL (fn)
4074 && (TREE_CODE (fn) == TEMPLATE_DECL
4075 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
4076 != NULL_TREE)))
4077 return true;
4080 return false;
4083 /* Returns true iff FN is a user-provided function, i.e. user-declared
4084 and not defaulted at its first declaration. */
4086 static bool
4087 user_provided_p (tree fn)
4089 if (TREE_CODE (fn) == TEMPLATE_DECL)
4090 return true;
4091 else
4092 return (!DECL_ARTIFICIAL (fn)
4093 && !(DECL_DEFAULTED_FN (fn)
4094 && DECL_INITIALIZED_IN_CLASS_P (fn)));
4097 /* Returns true iff class T has a user-provided constructor. */
4099 bool
4100 type_has_user_provided_constructor (tree t)
4102 tree fns;
4104 if (!CLASS_TYPE_P (t))
4105 return false;
4107 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4108 return false;
4110 /* This can happen in error cases; avoid crashing. */
4111 if (!CLASSTYPE_METHOD_VEC (t))
4112 return false;
4114 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4115 if (user_provided_p (OVL_CURRENT (fns)))
4116 return true;
4118 return false;
4121 /* Returns true iff class T has a user-provided default constructor. */
4123 bool
4124 type_has_user_provided_default_constructor (tree t)
4126 tree fns, args;
4128 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4129 return false;
4131 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4133 tree fn = OVL_CURRENT (fns);
4134 if (TREE_CODE (fn) == FUNCTION_DECL
4135 && user_provided_p (fn))
4137 args = FUNCTION_FIRST_USER_PARMTYPE (fn);
4138 while (args && TREE_PURPOSE (args))
4139 args = TREE_CHAIN (args);
4140 if (!args || args == void_list_node)
4141 return true;
4145 return false;
4148 /* Returns true if FN can be explicitly defaulted. */
4150 bool
4151 defaultable_fn_p (tree fn)
4153 if (DECL_CONSTRUCTOR_P (fn))
4155 if (FUNCTION_FIRST_USER_PARMTYPE (fn) == void_list_node)
4156 return true;
4157 else if (copy_fn_p (fn) > 0
4158 && (TREE_CHAIN (FUNCTION_FIRST_USER_PARMTYPE (fn))
4159 == void_list_node))
4160 return true;
4161 else
4162 return false;
4164 else if (DECL_DESTRUCTOR_P (fn))
4165 return true;
4166 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
4167 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
4168 return copy_fn_p (fn);
4169 else
4170 return false;
4173 /* Remove all zero-width bit-fields from T. */
4175 static void
4176 remove_zero_width_bit_fields (tree t)
4178 tree *fieldsp;
4180 fieldsp = &TYPE_FIELDS (t);
4181 while (*fieldsp)
4183 if (TREE_CODE (*fieldsp) == FIELD_DECL
4184 && DECL_C_BIT_FIELD (*fieldsp)
4185 && DECL_INITIAL (*fieldsp))
4186 *fieldsp = TREE_CHAIN (*fieldsp);
4187 else
4188 fieldsp = &TREE_CHAIN (*fieldsp);
4192 /* Returns TRUE iff we need a cookie when dynamically allocating an
4193 array whose elements have the indicated class TYPE. */
4195 static bool
4196 type_requires_array_cookie (tree type)
4198 tree fns;
4199 bool has_two_argument_delete_p = false;
4201 gcc_assert (CLASS_TYPE_P (type));
4203 /* If there's a non-trivial destructor, we need a cookie. In order
4204 to iterate through the array calling the destructor for each
4205 element, we'll have to know how many elements there are. */
4206 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4207 return true;
4209 /* If the usual deallocation function is a two-argument whose second
4210 argument is of type `size_t', then we have to pass the size of
4211 the array to the deallocation function, so we will need to store
4212 a cookie. */
4213 fns = lookup_fnfields (TYPE_BINFO (type),
4214 ansi_opname (VEC_DELETE_EXPR),
4215 /*protect=*/0);
4216 /* If there are no `operator []' members, or the lookup is
4217 ambiguous, then we don't need a cookie. */
4218 if (!fns || fns == error_mark_node)
4219 return false;
4220 /* Loop through all of the functions. */
4221 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4223 tree fn;
4224 tree second_parm;
4226 /* Select the current function. */
4227 fn = OVL_CURRENT (fns);
4228 /* See if this function is a one-argument delete function. If
4229 it is, then it will be the usual deallocation function. */
4230 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4231 if (second_parm == void_list_node)
4232 return false;
4233 /* Do not consider this function if its second argument is an
4234 ellipsis. */
4235 if (!second_parm)
4236 continue;
4237 /* Otherwise, if we have a two-argument function and the second
4238 argument is `size_t', it will be the usual deallocation
4239 function -- unless there is one-argument function, too. */
4240 if (TREE_CHAIN (second_parm) == void_list_node
4241 && same_type_p (TREE_VALUE (second_parm), size_type_node))
4242 has_two_argument_delete_p = true;
4245 return has_two_argument_delete_p;
4248 /* Check the validity of the bases and members declared in T. Add any
4249 implicitly-generated functions (like copy-constructors and
4250 assignment operators). Compute various flag bits (like
4251 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4252 level: i.e., independently of the ABI in use. */
4254 static void
4255 check_bases_and_members (tree t)
4257 /* Nonzero if the implicitly generated copy constructor should take
4258 a non-const reference argument. */
4259 int cant_have_const_ctor;
4260 /* Nonzero if the implicitly generated assignment operator
4261 should take a non-const reference argument. */
4262 int no_const_asn_ref;
4263 tree access_decls;
4264 bool saved_complex_asn_ref;
4265 bool saved_nontrivial_dtor;
4267 /* By default, we use const reference arguments and generate default
4268 constructors. */
4269 cant_have_const_ctor = 0;
4270 no_const_asn_ref = 0;
4272 /* Check all the base-classes. */
4273 check_bases (t, &cant_have_const_ctor,
4274 &no_const_asn_ref);
4276 /* Check all the method declarations. */
4277 check_methods (t);
4279 /* Save the initial values of these flags which only indicate whether
4280 or not the class has user-provided functions. As we analyze the
4281 bases and members we can set these flags for other reasons. */
4282 saved_complex_asn_ref = TYPE_HAS_COMPLEX_ASSIGN_REF (t);
4283 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
4285 /* Check all the data member declarations. We cannot call
4286 check_field_decls until we have called check_bases check_methods,
4287 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4288 being set appropriately. */
4289 check_field_decls (t, &access_decls,
4290 &cant_have_const_ctor,
4291 &no_const_asn_ref);
4293 /* A nearly-empty class has to be vptr-containing; a nearly empty
4294 class contains just a vptr. */
4295 if (!TYPE_CONTAINS_VPTR_P (t))
4296 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4298 /* Do some bookkeeping that will guide the generation of implicitly
4299 declared member functions. */
4300 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4301 /* We need to call a constructor for this class if it has a
4302 user-provided constructor, or if the default constructor is going
4303 to initialize the vptr. (This is not an if-and-only-if;
4304 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4305 themselves need constructing.) */
4306 TYPE_NEEDS_CONSTRUCTING (t)
4307 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t));
4308 /* [dcl.init.aggr]
4310 An aggregate is an array or a class with no user-provided
4311 constructors ... and no virtual functions.
4313 Again, other conditions for being an aggregate are checked
4314 elsewhere. */
4315 CLASSTYPE_NON_AGGREGATE (t)
4316 |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t));
4317 CLASSTYPE_NON_POD_P (t)
4318 |= (CLASSTYPE_NON_AGGREGATE (t)
4319 || saved_nontrivial_dtor || saved_complex_asn_ref);
4320 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4321 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
4323 /* If the class has no user-declared constructor, but does have
4324 non-static const or reference data members that can never be
4325 initialized, issue a warning. */
4326 if (warn_uninitialized
4327 /* Classes with user-declared constructors are presumed to
4328 initialize these members. */
4329 && !TYPE_HAS_USER_CONSTRUCTOR (t)
4330 /* Aggregates can be initialized with brace-enclosed
4331 initializers. */
4332 && CLASSTYPE_NON_AGGREGATE (t))
4334 tree field;
4336 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4338 tree type;
4340 if (TREE_CODE (field) != FIELD_DECL)
4341 continue;
4343 type = TREE_TYPE (field);
4344 if (TREE_CODE (type) == REFERENCE_TYPE)
4345 warning (OPT_Wuninitialized, "non-static reference %q+#D "
4346 "in class without a constructor", field);
4347 else if (CP_TYPE_CONST_P (type)
4348 && (!CLASS_TYPE_P (type)
4349 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type)))
4350 warning (OPT_Wuninitialized, "non-static const member %q+#D "
4351 "in class without a constructor", field);
4355 /* Synthesize any needed methods. */
4356 add_implicitly_declared_members (t,
4357 cant_have_const_ctor,
4358 no_const_asn_ref);
4360 /* Create the in-charge and not-in-charge variants of constructors
4361 and destructors. */
4362 clone_constructors_and_destructors (t);
4364 /* Process the using-declarations. */
4365 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4366 handle_using_decl (TREE_VALUE (access_decls), t);
4368 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4369 finish_struct_methods (t);
4371 /* Figure out whether or not we will need a cookie when dynamically
4372 allocating an array of this type. */
4373 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4374 = type_requires_array_cookie (t);
4377 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4378 accordingly. If a new vfield was created (because T doesn't have a
4379 primary base class), then the newly created field is returned. It
4380 is not added to the TYPE_FIELDS list; it is the caller's
4381 responsibility to do that. Accumulate declared virtual functions
4382 on VIRTUALS_P. */
4384 static tree
4385 create_vtable_ptr (tree t, tree* virtuals_p)
4387 tree fn;
4389 /* Collect the virtual functions declared in T. */
4390 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4391 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4392 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4394 tree new_virtual = make_node (TREE_LIST);
4396 BV_FN (new_virtual) = fn;
4397 BV_DELTA (new_virtual) = integer_zero_node;
4398 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4400 TREE_CHAIN (new_virtual) = *virtuals_p;
4401 *virtuals_p = new_virtual;
4404 /* If we couldn't find an appropriate base class, create a new field
4405 here. Even if there weren't any new virtual functions, we might need a
4406 new virtual function table if we're supposed to include vptrs in
4407 all classes that need them. */
4408 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4410 /* We build this decl with vtbl_ptr_type_node, which is a
4411 `vtable_entry_type*'. It might seem more precise to use
4412 `vtable_entry_type (*)[N]' where N is the number of virtual
4413 functions. However, that would require the vtable pointer in
4414 base classes to have a different type than the vtable pointer
4415 in derived classes. We could make that happen, but that
4416 still wouldn't solve all the problems. In particular, the
4417 type-based alias analysis code would decide that assignments
4418 to the base class vtable pointer can't alias assignments to
4419 the derived class vtable pointer, since they have different
4420 types. Thus, in a derived class destructor, where the base
4421 class constructor was inlined, we could generate bad code for
4422 setting up the vtable pointer.
4424 Therefore, we use one type for all vtable pointers. We still
4425 use a type-correct type; it's just doesn't indicate the array
4426 bounds. That's better than using `void*' or some such; it's
4427 cleaner, and it let's the alias analysis code know that these
4428 stores cannot alias stores to void*! */
4429 tree field;
4431 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4432 DECL_VIRTUAL_P (field) = 1;
4433 DECL_ARTIFICIAL (field) = 1;
4434 DECL_FIELD_CONTEXT (field) = t;
4435 DECL_FCONTEXT (field) = t;
4437 TYPE_VFIELD (t) = field;
4439 /* This class is non-empty. */
4440 CLASSTYPE_EMPTY_P (t) = 0;
4442 return field;
4445 return NULL_TREE;
4448 /* Fixup the inline function given by INFO now that the class is
4449 complete. */
4451 static void
4452 fixup_pending_inline (tree fn)
4454 if (DECL_PENDING_INLINE_INFO (fn))
4456 tree args = DECL_ARGUMENTS (fn);
4457 while (args)
4459 DECL_CONTEXT (args) = fn;
4460 args = TREE_CHAIN (args);
4465 /* Fixup the inline methods and friends in TYPE now that TYPE is
4466 complete. */
4468 static void
4469 fixup_inline_methods (tree type)
4471 tree method = TYPE_METHODS (type);
4472 VEC(tree,gc) *friends;
4473 unsigned ix;
4475 if (method && TREE_CODE (method) == TREE_VEC)
4477 if (TREE_VEC_ELT (method, 1))
4478 method = TREE_VEC_ELT (method, 1);
4479 else if (TREE_VEC_ELT (method, 0))
4480 method = TREE_VEC_ELT (method, 0);
4481 else
4482 method = TREE_VEC_ELT (method, 2);
4485 /* Do inline member functions. */
4486 for (; method; method = TREE_CHAIN (method))
4487 fixup_pending_inline (method);
4489 /* Do friends. */
4490 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4491 VEC_iterate (tree, friends, ix, method); ix++)
4492 fixup_pending_inline (method);
4493 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4496 /* Add OFFSET to all base types of BINFO which is a base in the
4497 hierarchy dominated by T.
4499 OFFSET, which is a type offset, is number of bytes. */
4501 static void
4502 propagate_binfo_offsets (tree binfo, tree offset)
4504 int i;
4505 tree primary_binfo;
4506 tree base_binfo;
4508 /* Update BINFO's offset. */
4509 BINFO_OFFSET (binfo)
4510 = convert (sizetype,
4511 size_binop (PLUS_EXPR,
4512 convert (ssizetype, BINFO_OFFSET (binfo)),
4513 offset));
4515 /* Find the primary base class. */
4516 primary_binfo = get_primary_binfo (binfo);
4518 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4519 propagate_binfo_offsets (primary_binfo, offset);
4521 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4522 downwards. */
4523 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4525 /* Don't do the primary base twice. */
4526 if (base_binfo == primary_binfo)
4527 continue;
4529 if (BINFO_VIRTUAL_P (base_binfo))
4530 continue;
4532 propagate_binfo_offsets (base_binfo, offset);
4536 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4537 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4538 empty subobjects of T. */
4540 static void
4541 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4543 tree vbase;
4544 tree t = rli->t;
4545 bool first_vbase = true;
4546 tree *next_field;
4548 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4549 return;
4551 if (!abi_version_at_least(2))
4553 /* In G++ 3.2, we incorrectly rounded the size before laying out
4554 the virtual bases. */
4555 finish_record_layout (rli, /*free_p=*/false);
4556 #ifdef STRUCTURE_SIZE_BOUNDARY
4557 /* Packed structures don't need to have minimum size. */
4558 if (! TYPE_PACKED (t))
4559 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4560 #endif
4561 rli->offset = TYPE_SIZE_UNIT (t);
4562 rli->bitpos = bitsize_zero_node;
4563 rli->record_align = TYPE_ALIGN (t);
4566 /* Find the last field. The artificial fields created for virtual
4567 bases will go after the last extant field to date. */
4568 next_field = &TYPE_FIELDS (t);
4569 while (*next_field)
4570 next_field = &TREE_CHAIN (*next_field);
4572 /* Go through the virtual bases, allocating space for each virtual
4573 base that is not already a primary base class. These are
4574 allocated in inheritance graph order. */
4575 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4577 if (!BINFO_VIRTUAL_P (vbase))
4578 continue;
4580 if (!BINFO_PRIMARY_P (vbase))
4582 tree basetype = TREE_TYPE (vbase);
4584 /* This virtual base is not a primary base of any class in the
4585 hierarchy, so we have to add space for it. */
4586 next_field = build_base_field (rli, vbase,
4587 offsets, next_field);
4589 /* If the first virtual base might have been placed at a
4590 lower address, had we started from CLASSTYPE_SIZE, rather
4591 than TYPE_SIZE, issue a warning. There can be both false
4592 positives and false negatives from this warning in rare
4593 cases; to deal with all the possibilities would probably
4594 require performing both layout algorithms and comparing
4595 the results which is not particularly tractable. */
4596 if (warn_abi
4597 && first_vbase
4598 && (tree_int_cst_lt
4599 (size_binop (CEIL_DIV_EXPR,
4600 round_up (CLASSTYPE_SIZE (t),
4601 CLASSTYPE_ALIGN (basetype)),
4602 bitsize_unit_node),
4603 BINFO_OFFSET (vbase))))
4604 warning (OPT_Wabi,
4605 "offset of virtual base %qT is not ABI-compliant and "
4606 "may change in a future version of GCC",
4607 basetype);
4609 first_vbase = false;
4614 /* Returns the offset of the byte just past the end of the base class
4615 BINFO. */
4617 static tree
4618 end_of_base (tree binfo)
4620 tree size;
4622 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo)))
4623 size = TYPE_SIZE_UNIT (char_type_node);
4624 else if (is_empty_class (BINFO_TYPE (binfo)))
4625 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4626 allocate some space for it. It cannot have virtual bases, so
4627 TYPE_SIZE_UNIT is fine. */
4628 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4629 else
4630 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4632 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4635 /* Returns the offset of the byte just past the end of the base class
4636 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4637 only non-virtual bases are included. */
4639 static tree
4640 end_of_class (tree t, int include_virtuals_p)
4642 tree result = size_zero_node;
4643 VEC(tree,gc) *vbases;
4644 tree binfo;
4645 tree base_binfo;
4646 tree offset;
4647 int i;
4649 for (binfo = TYPE_BINFO (t), i = 0;
4650 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4652 if (!include_virtuals_p
4653 && BINFO_VIRTUAL_P (base_binfo)
4654 && (!BINFO_PRIMARY_P (base_binfo)
4655 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4656 continue;
4658 offset = end_of_base (base_binfo);
4659 if (INT_CST_LT_UNSIGNED (result, offset))
4660 result = offset;
4663 /* G++ 3.2 did not check indirect virtual bases. */
4664 if (abi_version_at_least (2) && include_virtuals_p)
4665 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4666 VEC_iterate (tree, vbases, i, base_binfo); i++)
4668 offset = end_of_base (base_binfo);
4669 if (INT_CST_LT_UNSIGNED (result, offset))
4670 result = offset;
4673 return result;
4676 /* Warn about bases of T that are inaccessible because they are
4677 ambiguous. For example:
4679 struct S {};
4680 struct T : public S {};
4681 struct U : public S, public T {};
4683 Here, `(S*) new U' is not allowed because there are two `S'
4684 subobjects of U. */
4686 static void
4687 warn_about_ambiguous_bases (tree t)
4689 int i;
4690 VEC(tree,gc) *vbases;
4691 tree basetype;
4692 tree binfo;
4693 tree base_binfo;
4695 /* If there are no repeated bases, nothing can be ambiguous. */
4696 if (!CLASSTYPE_REPEATED_BASE_P (t))
4697 return;
4699 /* Check direct bases. */
4700 for (binfo = TYPE_BINFO (t), i = 0;
4701 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4703 basetype = BINFO_TYPE (base_binfo);
4705 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4706 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4707 basetype, t);
4710 /* Check for ambiguous virtual bases. */
4711 if (extra_warnings)
4712 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4713 VEC_iterate (tree, vbases, i, binfo); i++)
4715 basetype = BINFO_TYPE (binfo);
4717 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4718 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity",
4719 basetype, t);
4723 /* Compare two INTEGER_CSTs K1 and K2. */
4725 static int
4726 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4728 return tree_int_cst_compare ((tree) k1, (tree) k2);
4731 /* Increase the size indicated in RLI to account for empty classes
4732 that are "off the end" of the class. */
4734 static void
4735 include_empty_classes (record_layout_info rli)
4737 tree eoc;
4738 tree rli_size;
4740 /* It might be the case that we grew the class to allocate a
4741 zero-sized base class. That won't be reflected in RLI, yet,
4742 because we are willing to overlay multiple bases at the same
4743 offset. However, now we need to make sure that RLI is big enough
4744 to reflect the entire class. */
4745 eoc = end_of_class (rli->t,
4746 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4747 rli_size = rli_size_unit_so_far (rli);
4748 if (TREE_CODE (rli_size) == INTEGER_CST
4749 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4751 if (!abi_version_at_least (2))
4752 /* In version 1 of the ABI, the size of a class that ends with
4753 a bitfield was not rounded up to a whole multiple of a
4754 byte. Because rli_size_unit_so_far returns only the number
4755 of fully allocated bytes, any extra bits were not included
4756 in the size. */
4757 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4758 else
4759 /* The size should have been rounded to a whole byte. */
4760 gcc_assert (tree_int_cst_equal
4761 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4762 rli->bitpos
4763 = size_binop (PLUS_EXPR,
4764 rli->bitpos,
4765 size_binop (MULT_EXPR,
4766 convert (bitsizetype,
4767 size_binop (MINUS_EXPR,
4768 eoc, rli_size)),
4769 bitsize_int (BITS_PER_UNIT)));
4770 normalize_rli (rli);
4774 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4775 BINFO_OFFSETs for all of the base-classes. Position the vtable
4776 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4778 static void
4779 layout_class_type (tree t, tree *virtuals_p)
4781 tree non_static_data_members;
4782 tree field;
4783 tree vptr;
4784 record_layout_info rli;
4785 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4786 types that appear at that offset. */
4787 splay_tree empty_base_offsets;
4788 /* True if the last field layed out was a bit-field. */
4789 bool last_field_was_bitfield = false;
4790 /* The location at which the next field should be inserted. */
4791 tree *next_field;
4792 /* T, as a base class. */
4793 tree base_t;
4795 /* Keep track of the first non-static data member. */
4796 non_static_data_members = TYPE_FIELDS (t);
4798 /* Start laying out the record. */
4799 rli = start_record_layout (t);
4801 /* Mark all the primary bases in the hierarchy. */
4802 determine_primary_bases (t);
4804 /* Create a pointer to our virtual function table. */
4805 vptr = create_vtable_ptr (t, virtuals_p);
4807 /* The vptr is always the first thing in the class. */
4808 if (vptr)
4810 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4811 TYPE_FIELDS (t) = vptr;
4812 next_field = &TREE_CHAIN (vptr);
4813 place_field (rli, vptr);
4815 else
4816 next_field = &TYPE_FIELDS (t);
4818 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4819 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4820 NULL, NULL);
4821 build_base_fields (rli, empty_base_offsets, next_field);
4823 /* Layout the non-static data members. */
4824 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4826 tree type;
4827 tree padding;
4829 /* We still pass things that aren't non-static data members to
4830 the back end, in case it wants to do something with them. */
4831 if (TREE_CODE (field) != FIELD_DECL)
4833 place_field (rli, field);
4834 /* If the static data member has incomplete type, keep track
4835 of it so that it can be completed later. (The handling
4836 of pending statics in finish_record_layout is
4837 insufficient; consider:
4839 struct S1;
4840 struct S2 { static S1 s1; };
4842 At this point, finish_record_layout will be called, but
4843 S1 is still incomplete.) */
4844 if (TREE_CODE (field) == VAR_DECL)
4846 maybe_register_incomplete_var (field);
4847 /* The visibility of static data members is determined
4848 at their point of declaration, not their point of
4849 definition. */
4850 determine_visibility (field);
4852 continue;
4855 type = TREE_TYPE (field);
4856 if (type == error_mark_node)
4857 continue;
4859 padding = NULL_TREE;
4861 /* If this field is a bit-field whose width is greater than its
4862 type, then there are some special rules for allocating
4863 it. */
4864 if (DECL_C_BIT_FIELD (field)
4865 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4867 integer_type_kind itk;
4868 tree integer_type;
4869 bool was_unnamed_p = false;
4870 /* We must allocate the bits as if suitably aligned for the
4871 longest integer type that fits in this many bits. type
4872 of the field. Then, we are supposed to use the left over
4873 bits as additional padding. */
4874 for (itk = itk_char; itk != itk_none; ++itk)
4875 if (INT_CST_LT (DECL_SIZE (field),
4876 TYPE_SIZE (integer_types[itk])))
4877 break;
4879 /* ITK now indicates a type that is too large for the
4880 field. We have to back up by one to find the largest
4881 type that fits. */
4882 integer_type = integer_types[itk - 1];
4884 /* Figure out how much additional padding is required. GCC
4885 3.2 always created a padding field, even if it had zero
4886 width. */
4887 if (!abi_version_at_least (2)
4888 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4890 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4891 /* In a union, the padding field must have the full width
4892 of the bit-field; all fields start at offset zero. */
4893 padding = DECL_SIZE (field);
4894 else
4896 if (TREE_CODE (t) == UNION_TYPE)
4897 warning (OPT_Wabi, "size assigned to %qT may not be "
4898 "ABI-compliant and may change in a future "
4899 "version of GCC",
4901 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4902 TYPE_SIZE (integer_type));
4905 #ifdef PCC_BITFIELD_TYPE_MATTERS
4906 /* An unnamed bitfield does not normally affect the
4907 alignment of the containing class on a target where
4908 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4909 make any exceptions for unnamed bitfields when the
4910 bitfields are longer than their types. Therefore, we
4911 temporarily give the field a name. */
4912 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4914 was_unnamed_p = true;
4915 DECL_NAME (field) = make_anon_name ();
4917 #endif
4918 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4919 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4920 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4921 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4922 empty_base_offsets);
4923 if (was_unnamed_p)
4924 DECL_NAME (field) = NULL_TREE;
4925 /* Now that layout has been performed, set the size of the
4926 field to the size of its declared type; the rest of the
4927 field is effectively invisible. */
4928 DECL_SIZE (field) = TYPE_SIZE (type);
4929 /* We must also reset the DECL_MODE of the field. */
4930 if (abi_version_at_least (2))
4931 DECL_MODE (field) = TYPE_MODE (type);
4932 else if (warn_abi
4933 && DECL_MODE (field) != TYPE_MODE (type))
4934 /* Versions of G++ before G++ 3.4 did not reset the
4935 DECL_MODE. */
4936 warning (OPT_Wabi,
4937 "the offset of %qD may not be ABI-compliant and may "
4938 "change in a future version of GCC", field);
4940 else
4941 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4942 empty_base_offsets);
4944 /* Remember the location of any empty classes in FIELD. */
4945 if (abi_version_at_least (2))
4946 record_subobject_offsets (TREE_TYPE (field),
4947 byte_position(field),
4948 empty_base_offsets,
4949 /*is_data_member=*/true);
4951 /* If a bit-field does not immediately follow another bit-field,
4952 and yet it starts in the middle of a byte, we have failed to
4953 comply with the ABI. */
4954 if (warn_abi
4955 && DECL_C_BIT_FIELD (field)
4956 /* The TREE_NO_WARNING flag gets set by Objective-C when
4957 laying out an Objective-C class. The ObjC ABI differs
4958 from the C++ ABI, and so we do not want a warning
4959 here. */
4960 && !TREE_NO_WARNING (field)
4961 && !last_field_was_bitfield
4962 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4963 DECL_FIELD_BIT_OFFSET (field),
4964 bitsize_unit_node)))
4965 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
4966 "change in a future version of GCC", field);
4968 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4969 offset of the field. */
4970 if (warn_abi
4971 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4972 byte_position (field))
4973 && contains_empty_class_p (TREE_TYPE (field)))
4974 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
4975 "classes to be placed at different locations in a "
4976 "future version of GCC", field);
4978 /* The middle end uses the type of expressions to determine the
4979 possible range of expression values. In order to optimize
4980 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
4981 must be made aware of the width of "i", via its type.
4983 Because C++ does not have integer types of arbitrary width,
4984 we must (for the purposes of the front end) convert from the
4985 type assigned here to the declared type of the bitfield
4986 whenever a bitfield expression is used as an rvalue.
4987 Similarly, when assigning a value to a bitfield, the value
4988 must be converted to the type given the bitfield here. */
4989 if (DECL_C_BIT_FIELD (field))
4991 unsigned HOST_WIDE_INT width;
4992 tree ftype = TREE_TYPE (field);
4993 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
4994 if (width != TYPE_PRECISION (ftype))
4996 TREE_TYPE (field)
4997 = c_build_bitfield_integer_type (width,
4998 TYPE_UNSIGNED (ftype));
4999 TREE_TYPE (field)
5000 = cp_build_qualified_type (TREE_TYPE (field),
5001 TYPE_QUALS (ftype));
5005 /* If we needed additional padding after this field, add it
5006 now. */
5007 if (padding)
5009 tree padding_field;
5011 padding_field = build_decl (FIELD_DECL,
5012 NULL_TREE,
5013 char_type_node);
5014 DECL_BIT_FIELD (padding_field) = 1;
5015 DECL_SIZE (padding_field) = padding;
5016 DECL_CONTEXT (padding_field) = t;
5017 DECL_ARTIFICIAL (padding_field) = 1;
5018 DECL_IGNORED_P (padding_field) = 1;
5019 layout_nonempty_base_or_field (rli, padding_field,
5020 NULL_TREE,
5021 empty_base_offsets);
5024 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
5027 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
5029 /* Make sure that we are on a byte boundary so that the size of
5030 the class without virtual bases will always be a round number
5031 of bytes. */
5032 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
5033 normalize_rli (rli);
5036 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5037 padding. */
5038 if (!abi_version_at_least (2))
5039 include_empty_classes(rli);
5041 /* Delete all zero-width bit-fields from the list of fields. Now
5042 that the type is laid out they are no longer important. */
5043 remove_zero_width_bit_fields (t);
5045 /* Create the version of T used for virtual bases. We do not use
5046 make_class_type for this version; this is an artificial type. For
5047 a POD type, we just reuse T. */
5048 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
5050 base_t = make_node (TREE_CODE (t));
5052 /* Set the size and alignment for the new type. In G++ 3.2, all
5053 empty classes were considered to have size zero when used as
5054 base classes. */
5055 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
5057 TYPE_SIZE (base_t) = bitsize_zero_node;
5058 TYPE_SIZE_UNIT (base_t) = size_zero_node;
5059 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
5060 warning (OPT_Wabi,
5061 "layout of classes derived from empty class %qT "
5062 "may change in a future version of GCC",
5065 else
5067 tree eoc;
5069 /* If the ABI version is not at least two, and the last
5070 field was a bit-field, RLI may not be on a byte
5071 boundary. In particular, rli_size_unit_so_far might
5072 indicate the last complete byte, while rli_size_so_far
5073 indicates the total number of bits used. Therefore,
5074 rli_size_so_far, rather than rli_size_unit_so_far, is
5075 used to compute TYPE_SIZE_UNIT. */
5076 eoc = end_of_class (t, /*include_virtuals_p=*/0);
5077 TYPE_SIZE_UNIT (base_t)
5078 = size_binop (MAX_EXPR,
5079 convert (sizetype,
5080 size_binop (CEIL_DIV_EXPR,
5081 rli_size_so_far (rli),
5082 bitsize_int (BITS_PER_UNIT))),
5083 eoc);
5084 TYPE_SIZE (base_t)
5085 = size_binop (MAX_EXPR,
5086 rli_size_so_far (rli),
5087 size_binop (MULT_EXPR,
5088 convert (bitsizetype, eoc),
5089 bitsize_int (BITS_PER_UNIT)));
5091 TYPE_ALIGN (base_t) = rli->record_align;
5092 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
5094 /* Copy the fields from T. */
5095 next_field = &TYPE_FIELDS (base_t);
5096 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5097 if (TREE_CODE (field) == FIELD_DECL)
5099 *next_field = build_decl (FIELD_DECL,
5100 DECL_NAME (field),
5101 TREE_TYPE (field));
5102 DECL_CONTEXT (*next_field) = base_t;
5103 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
5104 DECL_FIELD_BIT_OFFSET (*next_field)
5105 = DECL_FIELD_BIT_OFFSET (field);
5106 DECL_SIZE (*next_field) = DECL_SIZE (field);
5107 DECL_MODE (*next_field) = DECL_MODE (field);
5108 next_field = &TREE_CHAIN (*next_field);
5111 /* Record the base version of the type. */
5112 CLASSTYPE_AS_BASE (t) = base_t;
5113 TYPE_CONTEXT (base_t) = t;
5115 else
5116 CLASSTYPE_AS_BASE (t) = t;
5118 /* Every empty class contains an empty class. */
5119 if (CLASSTYPE_EMPTY_P (t))
5120 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
5122 /* Set the TYPE_DECL for this type to contain the right
5123 value for DECL_OFFSET, so that we can use it as part
5124 of a COMPONENT_REF for multiple inheritance. */
5125 layout_decl (TYPE_MAIN_DECL (t), 0);
5127 /* Now fix up any virtual base class types that we left lying
5128 around. We must get these done before we try to lay out the
5129 virtual function table. As a side-effect, this will remove the
5130 base subobject fields. */
5131 layout_virtual_bases (rli, empty_base_offsets);
5133 /* Make sure that empty classes are reflected in RLI at this
5134 point. */
5135 include_empty_classes(rli);
5137 /* Make sure not to create any structures with zero size. */
5138 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
5139 place_field (rli,
5140 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
5142 /* Let the back end lay out the type. */
5143 finish_record_layout (rli, /*free_p=*/true);
5145 /* Warn about bases that can't be talked about due to ambiguity. */
5146 warn_about_ambiguous_bases (t);
5148 /* Now that we're done with layout, give the base fields the real types. */
5149 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5150 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
5151 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
5153 /* Clean up. */
5154 splay_tree_delete (empty_base_offsets);
5156 if (CLASSTYPE_EMPTY_P (t)
5157 && tree_int_cst_lt (sizeof_biggest_empty_class,
5158 TYPE_SIZE_UNIT (t)))
5159 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
5162 /* Determine the "key method" for the class type indicated by TYPE,
5163 and set CLASSTYPE_KEY_METHOD accordingly. */
5165 void
5166 determine_key_method (tree type)
5168 tree method;
5170 if (TYPE_FOR_JAVA (type)
5171 || processing_template_decl
5172 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
5173 || CLASSTYPE_INTERFACE_KNOWN (type))
5174 return;
5176 /* The key method is the first non-pure virtual function that is not
5177 inline at the point of class definition. On some targets the
5178 key function may not be inline; those targets should not call
5179 this function until the end of the translation unit. */
5180 for (method = TYPE_METHODS (type); method != NULL_TREE;
5181 method = TREE_CHAIN (method))
5182 if (DECL_VINDEX (method) != NULL_TREE
5183 && ! DECL_DECLARED_INLINE_P (method)
5184 && ! DECL_PURE_VIRTUAL_P (method))
5186 CLASSTYPE_KEY_METHOD (type) = method;
5187 break;
5190 return;
5193 /* Perform processing required when the definition of T (a class type)
5194 is complete. */
5196 void
5197 finish_struct_1 (tree t)
5199 tree x;
5200 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5201 tree virtuals = NULL_TREE;
5202 int n_fields = 0;
5204 if (COMPLETE_TYPE_P (t))
5206 gcc_assert (MAYBE_CLASS_TYPE_P (t));
5207 error ("redefinition of %q#T", t);
5208 popclass ();
5209 return;
5212 /* If this type was previously laid out as a forward reference,
5213 make sure we lay it out again. */
5214 TYPE_SIZE (t) = NULL_TREE;
5215 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
5217 fixup_inline_methods (t);
5219 /* Make assumptions about the class; we'll reset the flags if
5220 necessary. */
5221 CLASSTYPE_EMPTY_P (t) = 1;
5222 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
5223 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
5225 /* Do end-of-class semantic processing: checking the validity of the
5226 bases and members and add implicitly generated methods. */
5227 check_bases_and_members (t);
5229 /* Find the key method. */
5230 if (TYPE_CONTAINS_VPTR_P (t))
5232 /* The Itanium C++ ABI permits the key method to be chosen when
5233 the class is defined -- even though the key method so
5234 selected may later turn out to be an inline function. On
5235 some systems (such as ARM Symbian OS) the key method cannot
5236 be determined until the end of the translation unit. On such
5237 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5238 will cause the class to be added to KEYED_CLASSES. Then, in
5239 finish_file we will determine the key method. */
5240 if (targetm.cxx.key_method_may_be_inline ())
5241 determine_key_method (t);
5243 /* If a polymorphic class has no key method, we may emit the vtable
5244 in every translation unit where the class definition appears. */
5245 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
5246 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
5249 /* Layout the class itself. */
5250 layout_class_type (t, &virtuals);
5251 if (CLASSTYPE_AS_BASE (t) != t)
5252 /* We use the base type for trivial assignments, and hence it
5253 needs a mode. */
5254 compute_record_mode (CLASSTYPE_AS_BASE (t));
5256 virtuals = modify_all_vtables (t, nreverse (virtuals));
5258 /* If necessary, create the primary vtable for this class. */
5259 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
5261 /* We must enter these virtuals into the table. */
5262 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5263 build_primary_vtable (NULL_TREE, t);
5264 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
5265 /* Here we know enough to change the type of our virtual
5266 function table, but we will wait until later this function. */
5267 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
5270 if (TYPE_CONTAINS_VPTR_P (t))
5272 int vindex;
5273 tree fn;
5275 if (BINFO_VTABLE (TYPE_BINFO (t)))
5276 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5277 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5278 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5280 /* Add entries for virtual functions introduced by this class. */
5281 BINFO_VIRTUALS (TYPE_BINFO (t))
5282 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5284 /* Set DECL_VINDEX for all functions declared in this class. */
5285 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5287 fn = TREE_CHAIN (fn),
5288 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5289 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5291 tree fndecl = BV_FN (fn);
5293 if (DECL_THUNK_P (fndecl))
5294 /* A thunk. We should never be calling this entry directly
5295 from this vtable -- we'd use the entry for the non
5296 thunk base function. */
5297 DECL_VINDEX (fndecl) = NULL_TREE;
5298 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5299 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5303 finish_struct_bits (t);
5305 /* Complete the rtl for any static member objects of the type we're
5306 working on. */
5307 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5308 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5309 && TREE_TYPE (x) != error_mark_node
5310 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5311 DECL_MODE (x) = TYPE_MODE (t);
5313 /* Done with FIELDS...now decide whether to sort these for
5314 faster lookups later.
5316 We use a small number because most searches fail (succeeding
5317 ultimately as the search bores through the inheritance
5318 hierarchy), and we want this failure to occur quickly. */
5320 n_fields = count_fields (TYPE_FIELDS (t));
5321 if (n_fields > 7)
5323 struct sorted_fields_type *field_vec = GGC_NEWVAR
5324 (struct sorted_fields_type,
5325 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5326 field_vec->len = n_fields;
5327 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5328 qsort (field_vec->elts, n_fields, sizeof (tree),
5329 field_decl_cmp);
5330 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5331 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5332 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5335 /* Complain if one of the field types requires lower visibility. */
5336 constrain_class_visibility (t);
5338 /* Make the rtl for any new vtables we have created, and unmark
5339 the base types we marked. */
5340 finish_vtbls (t);
5342 /* Build the VTT for T. */
5343 build_vtt (t);
5345 /* This warning does not make sense for Java classes, since they
5346 cannot have destructors. */
5347 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5349 tree dtor;
5351 dtor = CLASSTYPE_DESTRUCTORS (t);
5352 if (/* An implicitly declared destructor is always public. And,
5353 if it were virtual, we would have created it by now. */
5354 !dtor
5355 || (!DECL_VINDEX (dtor)
5356 && (/* public non-virtual */
5357 (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
5358 || (/* non-public non-virtual with friends */
5359 (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
5360 && (CLASSTYPE_FRIEND_CLASSES (t)
5361 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
5362 warning (OPT_Wnon_virtual_dtor,
5363 "%q#T has virtual functions and accessible"
5364 " non-virtual destructor", t);
5367 complete_vars (t);
5369 if (warn_overloaded_virtual)
5370 warn_hidden (t);
5372 /* Class layout, assignment of virtual table slots, etc., is now
5373 complete. Give the back end a chance to tweak the visibility of
5374 the class or perform any other required target modifications. */
5375 targetm.cxx.adjust_class_at_definition (t);
5377 maybe_suppress_debug_info (t);
5379 dump_class_hierarchy (t);
5381 /* Finish debugging output for this type. */
5382 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5385 /* When T was built up, the member declarations were added in reverse
5386 order. Rearrange them to declaration order. */
5388 void
5389 unreverse_member_declarations (tree t)
5391 tree next;
5392 tree prev;
5393 tree x;
5395 /* The following lists are all in reverse order. Put them in
5396 declaration order now. */
5397 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5398 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5400 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5401 reverse order, so we can't just use nreverse. */
5402 prev = NULL_TREE;
5403 for (x = TYPE_FIELDS (t);
5404 x && TREE_CODE (x) != TYPE_DECL;
5405 x = next)
5407 next = TREE_CHAIN (x);
5408 TREE_CHAIN (x) = prev;
5409 prev = x;
5411 if (prev)
5413 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5414 if (prev)
5415 TYPE_FIELDS (t) = prev;
5419 tree
5420 finish_struct (tree t, tree attributes)
5422 location_t saved_loc = input_location;
5424 /* Now that we've got all the field declarations, reverse everything
5425 as necessary. */
5426 unreverse_member_declarations (t);
5428 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5430 /* Nadger the current location so that diagnostics point to the start of
5431 the struct, not the end. */
5432 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5434 if (processing_template_decl)
5436 tree x;
5438 finish_struct_methods (t);
5439 TYPE_SIZE (t) = bitsize_zero_node;
5440 TYPE_SIZE_UNIT (t) = size_zero_node;
5442 /* We need to emit an error message if this type was used as a parameter
5443 and it is an abstract type, even if it is a template. We construct
5444 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5445 account and we call complete_vars with this type, which will check
5446 the PARM_DECLS. Note that while the type is being defined,
5447 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5448 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5449 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5450 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5451 if (DECL_PURE_VIRTUAL_P (x))
5452 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5453 complete_vars (t);
5455 else
5456 finish_struct_1 (t);
5458 input_location = saved_loc;
5460 TYPE_BEING_DEFINED (t) = 0;
5462 if (current_class_type)
5463 popclass ();
5464 else
5465 error ("trying to finish struct, but kicked out due to previous parse errors");
5467 if (processing_template_decl && at_function_scope_p ())
5468 add_stmt (build_min (TAG_DEFN, t));
5470 return t;
5473 /* Return the dynamic type of INSTANCE, if known.
5474 Used to determine whether the virtual function table is needed
5475 or not.
5477 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5478 of our knowledge of its type. *NONNULL should be initialized
5479 before this function is called. */
5481 static tree
5482 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp)
5484 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5486 switch (TREE_CODE (instance))
5488 case INDIRECT_REF:
5489 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5490 return NULL_TREE;
5491 else
5492 return RECUR (TREE_OPERAND (instance, 0));
5494 case CALL_EXPR:
5495 /* This is a call to a constructor, hence it's never zero. */
5496 if (TREE_HAS_CONSTRUCTOR (instance))
5498 if (nonnull)
5499 *nonnull = 1;
5500 return TREE_TYPE (instance);
5502 return NULL_TREE;
5504 case SAVE_EXPR:
5505 /* This is a call to a constructor, hence it's never zero. */
5506 if (TREE_HAS_CONSTRUCTOR (instance))
5508 if (nonnull)
5509 *nonnull = 1;
5510 return TREE_TYPE (instance);
5512 return RECUR (TREE_OPERAND (instance, 0));
5514 case POINTER_PLUS_EXPR:
5515 case PLUS_EXPR:
5516 case MINUS_EXPR:
5517 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5518 return RECUR (TREE_OPERAND (instance, 0));
5519 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5520 /* Propagate nonnull. */
5521 return RECUR (TREE_OPERAND (instance, 0));
5523 return NULL_TREE;
5525 CASE_CONVERT:
5526 return RECUR (TREE_OPERAND (instance, 0));
5528 case ADDR_EXPR:
5529 instance = TREE_OPERAND (instance, 0);
5530 if (nonnull)
5532 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5533 with a real object -- given &p->f, p can still be null. */
5534 tree t = get_base_address (instance);
5535 /* ??? Probably should check DECL_WEAK here. */
5536 if (t && DECL_P (t))
5537 *nonnull = 1;
5539 return RECUR (instance);
5541 case COMPONENT_REF:
5542 /* If this component is really a base class reference, then the field
5543 itself isn't definitive. */
5544 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5545 return RECUR (TREE_OPERAND (instance, 0));
5546 return RECUR (TREE_OPERAND (instance, 1));
5548 case VAR_DECL:
5549 case FIELD_DECL:
5550 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5551 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
5553 if (nonnull)
5554 *nonnull = 1;
5555 return TREE_TYPE (TREE_TYPE (instance));
5557 /* fall through... */
5558 case TARGET_EXPR:
5559 case PARM_DECL:
5560 case RESULT_DECL:
5561 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance)))
5563 if (nonnull)
5564 *nonnull = 1;
5565 return TREE_TYPE (instance);
5567 else if (instance == current_class_ptr)
5569 if (nonnull)
5570 *nonnull = 1;
5572 /* if we're in a ctor or dtor, we know our type. */
5573 if (DECL_LANG_SPECIFIC (current_function_decl)
5574 && (DECL_CONSTRUCTOR_P (current_function_decl)
5575 || DECL_DESTRUCTOR_P (current_function_decl)))
5577 if (cdtorp)
5578 *cdtorp = 1;
5579 return TREE_TYPE (TREE_TYPE (instance));
5582 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5584 /* We only need one hash table because it is always left empty. */
5585 static htab_t ht;
5586 if (!ht)
5587 ht = htab_create (37,
5588 htab_hash_pointer,
5589 htab_eq_pointer,
5590 /*htab_del=*/NULL);
5592 /* Reference variables should be references to objects. */
5593 if (nonnull)
5594 *nonnull = 1;
5596 /* Enter the INSTANCE in a table to prevent recursion; a
5597 variable's initializer may refer to the variable
5598 itself. */
5599 if (TREE_CODE (instance) == VAR_DECL
5600 && DECL_INITIAL (instance)
5601 && !htab_find (ht, instance))
5603 tree type;
5604 void **slot;
5606 slot = htab_find_slot (ht, instance, INSERT);
5607 *slot = instance;
5608 type = RECUR (DECL_INITIAL (instance));
5609 htab_remove_elt (ht, instance);
5611 return type;
5614 return NULL_TREE;
5616 default:
5617 return NULL_TREE;
5619 #undef RECUR
5622 /* Return nonzero if the dynamic type of INSTANCE is known, and
5623 equivalent to the static type. We also handle the case where
5624 INSTANCE is really a pointer. Return negative if this is a
5625 ctor/dtor. There the dynamic type is known, but this might not be
5626 the most derived base of the original object, and hence virtual
5627 bases may not be layed out according to this type.
5629 Used to determine whether the virtual function table is needed
5630 or not.
5632 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5633 of our knowledge of its type. *NONNULL should be initialized
5634 before this function is called. */
5637 resolves_to_fixed_type_p (tree instance, int* nonnull)
5639 tree t = TREE_TYPE (instance);
5640 int cdtorp = 0;
5641 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5642 if (fixed == NULL_TREE)
5643 return 0;
5644 if (POINTER_TYPE_P (t))
5645 t = TREE_TYPE (t);
5646 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5647 return 0;
5648 return cdtorp ? -1 : 1;
5652 void
5653 init_class_processing (void)
5655 current_class_depth = 0;
5656 current_class_stack_size = 10;
5657 current_class_stack
5658 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5659 local_classes = VEC_alloc (tree, gc, 8);
5660 sizeof_biggest_empty_class = size_zero_node;
5662 ridpointers[(int) RID_PUBLIC] = access_public_node;
5663 ridpointers[(int) RID_PRIVATE] = access_private_node;
5664 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5667 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5669 static void
5670 restore_class_cache (void)
5672 tree type;
5674 /* We are re-entering the same class we just left, so we don't
5675 have to search the whole inheritance matrix to find all the
5676 decls to bind again. Instead, we install the cached
5677 class_shadowed list and walk through it binding names. */
5678 push_binding_level (previous_class_level);
5679 class_binding_level = previous_class_level;
5680 /* Restore IDENTIFIER_TYPE_VALUE. */
5681 for (type = class_binding_level->type_shadowed;
5682 type;
5683 type = TREE_CHAIN (type))
5684 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5687 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5688 appropriate for TYPE.
5690 So that we may avoid calls to lookup_name, we cache the _TYPE
5691 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5693 For multiple inheritance, we perform a two-pass depth-first search
5694 of the type lattice. */
5696 void
5697 pushclass (tree type)
5699 class_stack_node_t csn;
5701 type = TYPE_MAIN_VARIANT (type);
5703 /* Make sure there is enough room for the new entry on the stack. */
5704 if (current_class_depth + 1 >= current_class_stack_size)
5706 current_class_stack_size *= 2;
5707 current_class_stack
5708 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5709 current_class_stack_size);
5712 /* Insert a new entry on the class stack. */
5713 csn = current_class_stack + current_class_depth;
5714 csn->name = current_class_name;
5715 csn->type = current_class_type;
5716 csn->access = current_access_specifier;
5717 csn->names_used = 0;
5718 csn->hidden = 0;
5719 current_class_depth++;
5721 /* Now set up the new type. */
5722 current_class_name = TYPE_NAME (type);
5723 if (TREE_CODE (current_class_name) == TYPE_DECL)
5724 current_class_name = DECL_NAME (current_class_name);
5725 current_class_type = type;
5727 /* By default, things in classes are private, while things in
5728 structures or unions are public. */
5729 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5730 ? access_private_node
5731 : access_public_node);
5733 if (previous_class_level
5734 && type != previous_class_level->this_entity
5735 && current_class_depth == 1)
5737 /* Forcibly remove any old class remnants. */
5738 invalidate_class_lookup_cache ();
5741 if (!previous_class_level
5742 || type != previous_class_level->this_entity
5743 || current_class_depth > 1)
5744 pushlevel_class ();
5745 else
5746 restore_class_cache ();
5749 /* When we exit a toplevel class scope, we save its binding level so
5750 that we can restore it quickly. Here, we've entered some other
5751 class, so we must invalidate our cache. */
5753 void
5754 invalidate_class_lookup_cache (void)
5756 previous_class_level = NULL;
5759 /* Get out of the current class scope. If we were in a class scope
5760 previously, that is the one popped to. */
5762 void
5763 popclass (void)
5765 poplevel_class ();
5767 current_class_depth--;
5768 current_class_name = current_class_stack[current_class_depth].name;
5769 current_class_type = current_class_stack[current_class_depth].type;
5770 current_access_specifier = current_class_stack[current_class_depth].access;
5771 if (current_class_stack[current_class_depth].names_used)
5772 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5775 /* Mark the top of the class stack as hidden. */
5777 void
5778 push_class_stack (void)
5780 if (current_class_depth)
5781 ++current_class_stack[current_class_depth - 1].hidden;
5784 /* Mark the top of the class stack as un-hidden. */
5786 void
5787 pop_class_stack (void)
5789 if (current_class_depth)
5790 --current_class_stack[current_class_depth - 1].hidden;
5793 /* Returns 1 if the class type currently being defined is either T or
5794 a nested type of T. */
5796 bool
5797 currently_open_class (tree t)
5799 int i;
5801 if (!CLASS_TYPE_P (t))
5802 return false;
5804 /* We start looking from 1 because entry 0 is from global scope,
5805 and has no type. */
5806 for (i = current_class_depth; i > 0; --i)
5808 tree c;
5809 if (i == current_class_depth)
5810 c = current_class_type;
5811 else
5813 if (current_class_stack[i].hidden)
5814 break;
5815 c = current_class_stack[i].type;
5817 if (!c)
5818 continue;
5819 if (same_type_p (c, t))
5820 return true;
5822 return false;
5825 /* If either current_class_type or one of its enclosing classes are derived
5826 from T, return the appropriate type. Used to determine how we found
5827 something via unqualified lookup. */
5829 tree
5830 currently_open_derived_class (tree t)
5832 int i;
5834 /* The bases of a dependent type are unknown. */
5835 if (dependent_type_p (t))
5836 return NULL_TREE;
5838 if (!current_class_type)
5839 return NULL_TREE;
5841 if (DERIVED_FROM_P (t, current_class_type))
5842 return current_class_type;
5844 for (i = current_class_depth - 1; i > 0; --i)
5846 if (current_class_stack[i].hidden)
5847 break;
5848 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5849 return current_class_stack[i].type;
5852 return NULL_TREE;
5855 /* When entering a class scope, all enclosing class scopes' names with
5856 static meaning (static variables, static functions, types and
5857 enumerators) have to be visible. This recursive function calls
5858 pushclass for all enclosing class contexts until global or a local
5859 scope is reached. TYPE is the enclosed class. */
5861 void
5862 push_nested_class (tree type)
5864 /* A namespace might be passed in error cases, like A::B:C. */
5865 if (type == NULL_TREE
5866 || !CLASS_TYPE_P (type))
5867 return;
5869 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type)));
5871 pushclass (type);
5874 /* Undoes a push_nested_class call. */
5876 void
5877 pop_nested_class (void)
5879 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5881 popclass ();
5882 if (context && CLASS_TYPE_P (context))
5883 pop_nested_class ();
5886 /* Returns the number of extern "LANG" blocks we are nested within. */
5889 current_lang_depth (void)
5891 return VEC_length (tree, current_lang_base);
5894 /* Set global variables CURRENT_LANG_NAME to appropriate value
5895 so that behavior of name-mangling machinery is correct. */
5897 void
5898 push_lang_context (tree name)
5900 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5902 if (name == lang_name_cplusplus)
5904 current_lang_name = name;
5906 else if (name == lang_name_java)
5908 current_lang_name = name;
5909 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5910 (See record_builtin_java_type in decl.c.) However, that causes
5911 incorrect debug entries if these types are actually used.
5912 So we re-enable debug output after extern "Java". */
5913 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5914 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5915 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5916 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5917 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5918 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5919 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5920 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5922 else if (name == lang_name_c)
5924 current_lang_name = name;
5926 else
5927 error ("language string %<\"%E\"%> not recognized", name);
5930 /* Get out of the current language scope. */
5932 void
5933 pop_lang_context (void)
5935 current_lang_name = VEC_pop (tree, current_lang_base);
5938 /* Type instantiation routines. */
5940 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5941 matches the TARGET_TYPE. If there is no satisfactory match, return
5942 error_mark_node, and issue an error & warning messages under
5943 control of FLAGS. Permit pointers to member function if FLAGS
5944 permits. If TEMPLATE_ONLY, the name of the overloaded function was
5945 a template-id, and EXPLICIT_TARGS are the explicitly provided
5946 template arguments.
5948 If OVERLOAD is for one or more member functions, then ACCESS_PATH
5949 is the base path used to reference those member functions. If
5950 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
5951 resolved to a member function, access checks will be performed and
5952 errors issued if appropriate. */
5954 static tree
5955 resolve_address_of_overloaded_function (tree target_type,
5956 tree overload,
5957 tsubst_flags_t flags,
5958 bool template_only,
5959 tree explicit_targs,
5960 tree access_path)
5962 /* Here's what the standard says:
5964 [over.over]
5966 If the name is a function template, template argument deduction
5967 is done, and if the argument deduction succeeds, the deduced
5968 arguments are used to generate a single template function, which
5969 is added to the set of overloaded functions considered.
5971 Non-member functions and static member functions match targets of
5972 type "pointer-to-function" or "reference-to-function." Nonstatic
5973 member functions match targets of type "pointer-to-member
5974 function;" the function type of the pointer to member is used to
5975 select the member function from the set of overloaded member
5976 functions. If a nonstatic member function is selected, the
5977 reference to the overloaded function name is required to have the
5978 form of a pointer to member as described in 5.3.1.
5980 If more than one function is selected, any template functions in
5981 the set are eliminated if the set also contains a non-template
5982 function, and any given template function is eliminated if the
5983 set contains a second template function that is more specialized
5984 than the first according to the partial ordering rules 14.5.5.2.
5985 After such eliminations, if any, there shall remain exactly one
5986 selected function. */
5988 int is_ptrmem = 0;
5989 int is_reference = 0;
5990 /* We store the matches in a TREE_LIST rooted here. The functions
5991 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5992 interoperability with most_specialized_instantiation. */
5993 tree matches = NULL_TREE;
5994 tree fn;
5996 /* By the time we get here, we should be seeing only real
5997 pointer-to-member types, not the internal POINTER_TYPE to
5998 METHOD_TYPE representation. */
5999 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
6000 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
6002 gcc_assert (is_overloaded_fn (overload));
6004 /* Check that the TARGET_TYPE is reasonable. */
6005 if (TYPE_PTRFN_P (target_type))
6006 /* This is OK. */;
6007 else if (TYPE_PTRMEMFUNC_P (target_type))
6008 /* This is OK, too. */
6009 is_ptrmem = 1;
6010 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
6012 /* This is OK, too. This comes from a conversion to reference
6013 type. */
6014 target_type = build_reference_type (target_type);
6015 is_reference = 1;
6017 else
6019 if (flags & tf_error)
6020 error ("cannot resolve overloaded function %qD based on"
6021 " conversion to type %qT",
6022 DECL_NAME (OVL_FUNCTION (overload)), target_type);
6023 return error_mark_node;
6026 /* If we can find a non-template function that matches, we can just
6027 use it. There's no point in generating template instantiations
6028 if we're just going to throw them out anyhow. But, of course, we
6029 can only do this when we don't *need* a template function. */
6030 if (!template_only)
6032 tree fns;
6034 for (fns = overload; fns; fns = OVL_NEXT (fns))
6036 tree fn = OVL_CURRENT (fns);
6037 tree fntype;
6039 if (TREE_CODE (fn) == TEMPLATE_DECL)
6040 /* We're not looking for templates just yet. */
6041 continue;
6043 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6044 != is_ptrmem)
6045 /* We're looking for a non-static member, and this isn't
6046 one, or vice versa. */
6047 continue;
6049 /* Ignore functions which haven't been explicitly
6050 declared. */
6051 if (DECL_ANTICIPATED (fn))
6052 continue;
6054 /* See if there's a match. */
6055 fntype = TREE_TYPE (fn);
6056 if (is_ptrmem)
6057 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
6058 else if (!is_reference)
6059 fntype = build_pointer_type (fntype);
6061 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
6062 matches = tree_cons (fn, NULL_TREE, matches);
6066 /* Now, if we've already got a match (or matches), there's no need
6067 to proceed to the template functions. But, if we don't have a
6068 match we need to look at them, too. */
6069 if (!matches)
6071 tree target_fn_type;
6072 tree target_arg_types;
6073 tree target_ret_type;
6074 tree fns;
6076 if (is_ptrmem)
6077 target_fn_type
6078 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
6079 else
6080 target_fn_type = TREE_TYPE (target_type);
6081 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
6082 target_ret_type = TREE_TYPE (target_fn_type);
6084 /* Never do unification on the 'this' parameter. */
6085 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
6086 target_arg_types = TREE_CHAIN (target_arg_types);
6088 for (fns = overload; fns; fns = OVL_NEXT (fns))
6090 tree fn = OVL_CURRENT (fns);
6091 tree instantiation;
6092 tree instantiation_type;
6093 tree targs;
6095 if (TREE_CODE (fn) != TEMPLATE_DECL)
6096 /* We're only looking for templates. */
6097 continue;
6099 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6100 != is_ptrmem)
6101 /* We're not looking for a non-static member, and this is
6102 one, or vice versa. */
6103 continue;
6105 /* Try to do argument deduction. */
6106 targs = make_tree_vec (DECL_NTPARMS (fn));
6107 if (fn_type_unification (fn, explicit_targs, targs,
6108 target_arg_types, target_ret_type,
6109 DEDUCE_EXACT, LOOKUP_NORMAL))
6110 /* Argument deduction failed. */
6111 continue;
6113 /* Instantiate the template. */
6114 instantiation = instantiate_template (fn, targs, flags);
6115 if (instantiation == error_mark_node)
6116 /* Instantiation failed. */
6117 continue;
6119 /* See if there's a match. */
6120 instantiation_type = TREE_TYPE (instantiation);
6121 if (is_ptrmem)
6122 instantiation_type =
6123 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
6124 else if (!is_reference)
6125 instantiation_type = build_pointer_type (instantiation_type);
6126 if (can_convert_arg (target_type, instantiation_type, instantiation,
6127 LOOKUP_NORMAL))
6128 matches = tree_cons (instantiation, fn, matches);
6131 /* Now, remove all but the most specialized of the matches. */
6132 if (matches)
6134 tree match = most_specialized_instantiation (matches);
6136 if (match != error_mark_node)
6137 matches = tree_cons (TREE_PURPOSE (match),
6138 NULL_TREE,
6139 NULL_TREE);
6143 /* Now we should have exactly one function in MATCHES. */
6144 if (matches == NULL_TREE)
6146 /* There were *no* matches. */
6147 if (flags & tf_error)
6149 error ("no matches converting function %qD to type %q#T",
6150 DECL_NAME (OVL_FUNCTION (overload)),
6151 target_type);
6153 /* print_candidates expects a chain with the functions in
6154 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6155 so why be clever?). */
6156 for (; overload; overload = OVL_NEXT (overload))
6157 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
6158 matches);
6160 print_candidates (matches);
6162 return error_mark_node;
6164 else if (TREE_CHAIN (matches))
6166 /* There were too many matches. First check if they're all
6167 the same function. */
6168 tree match;
6170 fn = TREE_PURPOSE (matches);
6171 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match))
6172 if (!decls_match (fn, TREE_PURPOSE (matches)))
6173 break;
6175 if (match)
6177 if (flags & tf_error)
6179 error ("converting overloaded function %qD to type %q#T is ambiguous",
6180 DECL_NAME (OVL_FUNCTION (overload)),
6181 target_type);
6183 /* Since print_candidates expects the functions in the
6184 TREE_VALUE slot, we flip them here. */
6185 for (match = matches; match; match = TREE_CHAIN (match))
6186 TREE_VALUE (match) = TREE_PURPOSE (match);
6188 print_candidates (matches);
6191 return error_mark_node;
6195 /* Good, exactly one match. Now, convert it to the correct type. */
6196 fn = TREE_PURPOSE (matches);
6198 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
6199 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
6201 static int explained;
6203 if (!(flags & tf_error))
6204 return error_mark_node;
6206 permerror (input_location, "assuming pointer to member %qD", fn);
6207 if (!explained)
6209 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn);
6210 explained = 1;
6214 /* If we're doing overload resolution purely for the purpose of
6215 determining conversion sequences, we should not consider the
6216 function used. If this conversion sequence is selected, the
6217 function will be marked as used at this point. */
6218 if (!(flags & tf_conv))
6220 /* Make =delete work with SFINAE. */
6221 if (DECL_DELETED_FN (fn) && !(flags & tf_error))
6222 return error_mark_node;
6224 mark_used (fn);
6227 /* We could not check access to member functions when this
6228 expression was originally created since we did not know at that
6229 time to which function the expression referred. */
6230 if (!(flags & tf_no_access_control)
6231 && DECL_FUNCTION_MEMBER_P (fn))
6233 gcc_assert (access_path);
6234 perform_or_defer_access_check (access_path, fn, fn);
6237 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
6238 return cp_build_unary_op (ADDR_EXPR, fn, 0, flags);
6239 else
6241 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6242 will mark the function as addressed, but here we must do it
6243 explicitly. */
6244 cxx_mark_addressable (fn);
6246 return fn;
6250 /* This function will instantiate the type of the expression given in
6251 RHS to match the type of LHSTYPE. If errors exist, then return
6252 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6253 we complain on errors. If we are not complaining, never modify rhs,
6254 as overload resolution wants to try many possible instantiations, in
6255 the hope that at least one will work.
6257 For non-recursive calls, LHSTYPE should be a function, pointer to
6258 function, or a pointer to member function. */
6260 tree
6261 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
6263 tsubst_flags_t flags_in = flags;
6264 tree access_path = NULL_TREE;
6266 flags &= ~tf_ptrmem_ok;
6268 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
6270 if (flags & tf_error)
6271 error ("not enough type information");
6272 return error_mark_node;
6275 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
6277 if (same_type_p (lhstype, TREE_TYPE (rhs)))
6278 return rhs;
6279 if (flag_ms_extensions
6280 && TYPE_PTRMEMFUNC_P (lhstype)
6281 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
6282 /* Microsoft allows `A::f' to be resolved to a
6283 pointer-to-member. */
6285 else
6287 if (flags & tf_error)
6288 error ("argument of type %qT does not match %qT",
6289 TREE_TYPE (rhs), lhstype);
6290 return error_mark_node;
6294 if (TREE_CODE (rhs) == BASELINK)
6296 access_path = BASELINK_ACCESS_BINFO (rhs);
6297 rhs = BASELINK_FUNCTIONS (rhs);
6300 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6301 deduce any type information. */
6302 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
6304 if (flags & tf_error)
6305 error ("not enough type information");
6306 return error_mark_node;
6309 /* There only a few kinds of expressions that may have a type
6310 dependent on overload resolution. */
6311 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
6312 || TREE_CODE (rhs) == COMPONENT_REF
6313 || TREE_CODE (rhs) == COMPOUND_EXPR
6314 || really_overloaded_fn (rhs));
6316 /* We don't overwrite rhs if it is an overloaded function.
6317 Copying it would destroy the tree link. */
6318 if (TREE_CODE (rhs) != OVERLOAD)
6319 rhs = copy_node (rhs);
6321 /* This should really only be used when attempting to distinguish
6322 what sort of a pointer to function we have. For now, any
6323 arithmetic operation which is not supported on pointers
6324 is rejected as an error. */
6326 switch (TREE_CODE (rhs))
6328 case COMPONENT_REF:
6330 tree member = TREE_OPERAND (rhs, 1);
6332 member = instantiate_type (lhstype, member, flags);
6333 if (member != error_mark_node
6334 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6335 /* Do not lose object's side effects. */
6336 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6337 TREE_OPERAND (rhs, 0), member);
6338 return member;
6341 case OFFSET_REF:
6342 rhs = TREE_OPERAND (rhs, 1);
6343 if (BASELINK_P (rhs))
6344 return instantiate_type (lhstype, rhs, flags_in);
6346 /* This can happen if we are forming a pointer-to-member for a
6347 member template. */
6348 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6350 /* Fall through. */
6352 case TEMPLATE_ID_EXPR:
6354 tree fns = TREE_OPERAND (rhs, 0);
6355 tree args = TREE_OPERAND (rhs, 1);
6357 return
6358 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6359 /*template_only=*/true,
6360 args, access_path);
6363 case OVERLOAD:
6364 case FUNCTION_DECL:
6365 return
6366 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6367 /*template_only=*/false,
6368 /*explicit_targs=*/NULL_TREE,
6369 access_path);
6371 case COMPOUND_EXPR:
6372 TREE_OPERAND (rhs, 0)
6373 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6374 if (TREE_OPERAND (rhs, 0) == error_mark_node)
6375 return error_mark_node;
6376 TREE_OPERAND (rhs, 1)
6377 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6378 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6379 return error_mark_node;
6381 TREE_TYPE (rhs) = lhstype;
6382 return rhs;
6384 case ADDR_EXPR:
6386 if (PTRMEM_OK_P (rhs))
6387 flags |= tf_ptrmem_ok;
6389 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6392 case ERROR_MARK:
6393 return error_mark_node;
6395 default:
6396 gcc_unreachable ();
6398 return error_mark_node;
6401 /* Return the name of the virtual function pointer field
6402 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6403 this may have to look back through base types to find the
6404 ultimate field name. (For single inheritance, these could
6405 all be the same name. Who knows for multiple inheritance). */
6407 static tree
6408 get_vfield_name (tree type)
6410 tree binfo, base_binfo;
6411 char *buf;
6413 for (binfo = TYPE_BINFO (type);
6414 BINFO_N_BASE_BINFOS (binfo);
6415 binfo = base_binfo)
6417 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6419 if (BINFO_VIRTUAL_P (base_binfo)
6420 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6421 break;
6424 type = BINFO_TYPE (binfo);
6425 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
6426 + TYPE_NAME_LENGTH (type) + 2);
6427 sprintf (buf, VFIELD_NAME_FORMAT,
6428 IDENTIFIER_POINTER (constructor_name (type)));
6429 return get_identifier (buf);
6432 void
6433 print_class_statistics (void)
6435 #ifdef GATHER_STATISTICS
6436 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6437 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6438 if (n_vtables)
6440 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6441 n_vtables, n_vtable_searches);
6442 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6443 n_vtable_entries, n_vtable_elems);
6445 #endif
6448 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6449 according to [class]:
6450 The class-name is also inserted
6451 into the scope of the class itself. For purposes of access checking,
6452 the inserted class name is treated as if it were a public member name. */
6454 void
6455 build_self_reference (void)
6457 tree name = constructor_name (current_class_type);
6458 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6459 tree saved_cas;
6461 DECL_NONLOCAL (value) = 1;
6462 DECL_CONTEXT (value) = current_class_type;
6463 DECL_ARTIFICIAL (value) = 1;
6464 SET_DECL_SELF_REFERENCE_P (value);
6466 if (processing_template_decl)
6467 value = push_template_decl (value);
6469 saved_cas = current_access_specifier;
6470 current_access_specifier = access_public_node;
6471 finish_member_declaration (value);
6472 current_access_specifier = saved_cas;
6475 /* Returns 1 if TYPE contains only padding bytes. */
6478 is_empty_class (tree type)
6480 if (type == error_mark_node)
6481 return 0;
6483 if (! CLASS_TYPE_P (type))
6484 return 0;
6486 /* In G++ 3.2, whether or not a class was empty was determined by
6487 looking at its size. */
6488 if (abi_version_at_least (2))
6489 return CLASSTYPE_EMPTY_P (type);
6490 else
6491 return integer_zerop (CLASSTYPE_SIZE (type));
6494 /* Returns true if TYPE contains an empty class. */
6496 static bool
6497 contains_empty_class_p (tree type)
6499 if (is_empty_class (type))
6500 return true;
6501 if (CLASS_TYPE_P (type))
6503 tree field;
6504 tree binfo;
6505 tree base_binfo;
6506 int i;
6508 for (binfo = TYPE_BINFO (type), i = 0;
6509 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6510 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6511 return true;
6512 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6513 if (TREE_CODE (field) == FIELD_DECL
6514 && !DECL_ARTIFICIAL (field)
6515 && is_empty_class (TREE_TYPE (field)))
6516 return true;
6518 else if (TREE_CODE (type) == ARRAY_TYPE)
6519 return contains_empty_class_p (TREE_TYPE (type));
6520 return false;
6523 /* Returns true if TYPE contains no actual data, just various
6524 possible combinations of empty classes. */
6526 bool
6527 is_really_empty_class (tree type)
6529 if (is_empty_class (type))
6530 return true;
6531 if (CLASS_TYPE_P (type))
6533 tree field;
6534 tree binfo;
6535 tree base_binfo;
6536 int i;
6538 for (binfo = TYPE_BINFO (type), i = 0;
6539 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6540 if (!is_really_empty_class (BINFO_TYPE (base_binfo)))
6541 return false;
6542 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6543 if (TREE_CODE (field) == FIELD_DECL
6544 && !DECL_ARTIFICIAL (field)
6545 && !is_really_empty_class (TREE_TYPE (field)))
6546 return false;
6547 return true;
6549 else if (TREE_CODE (type) == ARRAY_TYPE)
6550 return is_really_empty_class (TREE_TYPE (type));
6551 return false;
6554 /* Note that NAME was looked up while the current class was being
6555 defined and that the result of that lookup was DECL. */
6557 void
6558 maybe_note_name_used_in_class (tree name, tree decl)
6560 splay_tree names_used;
6562 /* If we're not defining a class, there's nothing to do. */
6563 if (!(innermost_scope_kind() == sk_class
6564 && TYPE_BEING_DEFINED (current_class_type)))
6565 return;
6567 /* If there's already a binding for this NAME, then we don't have
6568 anything to worry about. */
6569 if (lookup_member (current_class_type, name,
6570 /*protect=*/0, /*want_type=*/false))
6571 return;
6573 if (!current_class_stack[current_class_depth - 1].names_used)
6574 current_class_stack[current_class_depth - 1].names_used
6575 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6576 names_used = current_class_stack[current_class_depth - 1].names_used;
6578 splay_tree_insert (names_used,
6579 (splay_tree_key) name,
6580 (splay_tree_value) decl);
6583 /* Note that NAME was declared (as DECL) in the current class. Check
6584 to see that the declaration is valid. */
6586 void
6587 note_name_declared_in_class (tree name, tree decl)
6589 splay_tree names_used;
6590 splay_tree_node n;
6592 /* Look to see if we ever used this name. */
6593 names_used
6594 = current_class_stack[current_class_depth - 1].names_used;
6595 if (!names_used)
6596 return;
6598 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6599 if (n)
6601 /* [basic.scope.class]
6603 A name N used in a class S shall refer to the same declaration
6604 in its context and when re-evaluated in the completed scope of
6605 S. */
6606 permerror (input_location, "declaration of %q#D", decl);
6607 permerror (input_location, "changes meaning of %qD from %q+#D",
6608 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6612 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6613 Secondary vtables are merged with primary vtables; this function
6614 will return the VAR_DECL for the primary vtable. */
6616 tree
6617 get_vtbl_decl_for_binfo (tree binfo)
6619 tree decl;
6621 decl = BINFO_VTABLE (binfo);
6622 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR)
6624 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6625 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6627 if (decl)
6628 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6629 return decl;
6633 /* Returns the binfo for the primary base of BINFO. If the resulting
6634 BINFO is a virtual base, and it is inherited elsewhere in the
6635 hierarchy, then the returned binfo might not be the primary base of
6636 BINFO in the complete object. Check BINFO_PRIMARY_P or
6637 BINFO_LOST_PRIMARY_P to be sure. */
6639 static tree
6640 get_primary_binfo (tree binfo)
6642 tree primary_base;
6644 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6645 if (!primary_base)
6646 return NULL_TREE;
6648 return copied_binfo (primary_base, binfo);
6651 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6653 static int
6654 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6656 if (!indented_p)
6657 fprintf (stream, "%*s", indent, "");
6658 return 1;
6661 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6662 INDENT should be zero when called from the top level; it is
6663 incremented recursively. IGO indicates the next expected BINFO in
6664 inheritance graph ordering. */
6666 static tree
6667 dump_class_hierarchy_r (FILE *stream,
6668 int flags,
6669 tree binfo,
6670 tree igo,
6671 int indent)
6673 int indented = 0;
6674 tree base_binfo;
6675 int i;
6677 indented = maybe_indent_hierarchy (stream, indent, 0);
6678 fprintf (stream, "%s (0x%lx) ",
6679 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6680 (unsigned long) binfo);
6681 if (binfo != igo)
6683 fprintf (stream, "alternative-path\n");
6684 return igo;
6686 igo = TREE_CHAIN (binfo);
6688 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6689 tree_low_cst (BINFO_OFFSET (binfo), 0));
6690 if (is_empty_class (BINFO_TYPE (binfo)))
6691 fprintf (stream, " empty");
6692 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6693 fprintf (stream, " nearly-empty");
6694 if (BINFO_VIRTUAL_P (binfo))
6695 fprintf (stream, " virtual");
6696 fprintf (stream, "\n");
6698 indented = 0;
6699 if (BINFO_PRIMARY_P (binfo))
6701 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6702 fprintf (stream, " primary-for %s (0x%lx)",
6703 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6704 TFF_PLAIN_IDENTIFIER),
6705 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6707 if (BINFO_LOST_PRIMARY_P (binfo))
6709 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6710 fprintf (stream, " lost-primary");
6712 if (indented)
6713 fprintf (stream, "\n");
6715 if (!(flags & TDF_SLIM))
6717 int indented = 0;
6719 if (BINFO_SUBVTT_INDEX (binfo))
6721 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6722 fprintf (stream, " subvttidx=%s",
6723 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6724 TFF_PLAIN_IDENTIFIER));
6726 if (BINFO_VPTR_INDEX (binfo))
6728 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6729 fprintf (stream, " vptridx=%s",
6730 expr_as_string (BINFO_VPTR_INDEX (binfo),
6731 TFF_PLAIN_IDENTIFIER));
6733 if (BINFO_VPTR_FIELD (binfo))
6735 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6736 fprintf (stream, " vbaseoffset=%s",
6737 expr_as_string (BINFO_VPTR_FIELD (binfo),
6738 TFF_PLAIN_IDENTIFIER));
6740 if (BINFO_VTABLE (binfo))
6742 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6743 fprintf (stream, " vptr=%s",
6744 expr_as_string (BINFO_VTABLE (binfo),
6745 TFF_PLAIN_IDENTIFIER));
6748 if (indented)
6749 fprintf (stream, "\n");
6752 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6753 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6755 return igo;
6758 /* Dump the BINFO hierarchy for T. */
6760 static void
6761 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6763 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6764 fprintf (stream, " size=%lu align=%lu\n",
6765 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6766 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6767 fprintf (stream, " base size=%lu base align=%lu\n",
6768 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6769 / BITS_PER_UNIT),
6770 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6771 / BITS_PER_UNIT));
6772 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6773 fprintf (stream, "\n");
6776 /* Debug interface to hierarchy dumping. */
6778 void
6779 debug_class (tree t)
6781 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6784 static void
6785 dump_class_hierarchy (tree t)
6787 int flags;
6788 FILE *stream = dump_begin (TDI_class, &flags);
6790 if (stream)
6792 dump_class_hierarchy_1 (stream, flags, t);
6793 dump_end (TDI_class, stream);
6797 static void
6798 dump_array (FILE * stream, tree decl)
6800 tree value;
6801 unsigned HOST_WIDE_INT ix;
6802 HOST_WIDE_INT elt;
6803 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6805 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6806 / BITS_PER_UNIT);
6807 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6808 fprintf (stream, " %s entries",
6809 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6810 TFF_PLAIN_IDENTIFIER));
6811 fprintf (stream, "\n");
6813 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6814 ix, value)
6815 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6816 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6819 static void
6820 dump_vtable (tree t, tree binfo, tree vtable)
6822 int flags;
6823 FILE *stream = dump_begin (TDI_class, &flags);
6825 if (!stream)
6826 return;
6828 if (!(flags & TDF_SLIM))
6830 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6832 fprintf (stream, "%s for %s",
6833 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6834 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6835 if (ctor_vtbl_p)
6837 if (!BINFO_VIRTUAL_P (binfo))
6838 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6839 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6841 fprintf (stream, "\n");
6842 dump_array (stream, vtable);
6843 fprintf (stream, "\n");
6846 dump_end (TDI_class, stream);
6849 static void
6850 dump_vtt (tree t, tree vtt)
6852 int flags;
6853 FILE *stream = dump_begin (TDI_class, &flags);
6855 if (!stream)
6856 return;
6858 if (!(flags & TDF_SLIM))
6860 fprintf (stream, "VTT for %s\n",
6861 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6862 dump_array (stream, vtt);
6863 fprintf (stream, "\n");
6866 dump_end (TDI_class, stream);
6869 /* Dump a function or thunk and its thunkees. */
6871 static void
6872 dump_thunk (FILE *stream, int indent, tree thunk)
6874 static const char spaces[] = " ";
6875 tree name = DECL_NAME (thunk);
6876 tree thunks;
6878 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6879 (void *)thunk,
6880 !DECL_THUNK_P (thunk) ? "function"
6881 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6882 name ? IDENTIFIER_POINTER (name) : "<unset>");
6883 if (DECL_THUNK_P (thunk))
6885 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6886 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6888 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6889 if (!virtual_adjust)
6890 /*NOP*/;
6891 else if (DECL_THIS_THUNK_P (thunk))
6892 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6893 tree_low_cst (virtual_adjust, 0));
6894 else
6895 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6896 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6897 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6898 if (THUNK_ALIAS (thunk))
6899 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6901 fprintf (stream, "\n");
6902 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6903 dump_thunk (stream, indent + 2, thunks);
6906 /* Dump the thunks for FN. */
6908 void
6909 debug_thunks (tree fn)
6911 dump_thunk (stderr, 0, fn);
6914 /* Virtual function table initialization. */
6916 /* Create all the necessary vtables for T and its base classes. */
6918 static void
6919 finish_vtbls (tree t)
6921 tree list;
6922 tree vbase;
6924 /* We lay out the primary and secondary vtables in one contiguous
6925 vtable. The primary vtable is first, followed by the non-virtual
6926 secondary vtables in inheritance graph order. */
6927 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6928 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6929 TYPE_BINFO (t), t, list);
6931 /* Then come the virtual bases, also in inheritance graph order. */
6932 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6934 if (!BINFO_VIRTUAL_P (vbase))
6935 continue;
6936 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6939 if (BINFO_VTABLE (TYPE_BINFO (t)))
6940 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6943 /* Initialize the vtable for BINFO with the INITS. */
6945 static void
6946 initialize_vtable (tree binfo, tree inits)
6948 tree decl;
6950 layout_vtable_decl (binfo, list_length (inits));
6951 decl = get_vtbl_decl_for_binfo (binfo);
6952 initialize_artificial_var (decl, inits);
6953 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6956 /* Build the VTT (virtual table table) for T.
6957 A class requires a VTT if it has virtual bases.
6959 This holds
6960 1 - primary virtual pointer for complete object T
6961 2 - secondary VTTs for each direct non-virtual base of T which requires a
6963 3 - secondary virtual pointers for each direct or indirect base of T which
6964 has virtual bases or is reachable via a virtual path from T.
6965 4 - secondary VTTs for each direct or indirect virtual base of T.
6967 Secondary VTTs look like complete object VTTs without part 4. */
6969 static void
6970 build_vtt (tree t)
6972 tree inits;
6973 tree type;
6974 tree vtt;
6975 tree index;
6977 /* Build up the initializers for the VTT. */
6978 inits = NULL_TREE;
6979 index = size_zero_node;
6980 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6982 /* If we didn't need a VTT, we're done. */
6983 if (!inits)
6984 return;
6986 /* Figure out the type of the VTT. */
6987 type = build_index_type (size_int (list_length (inits) - 1));
6988 type = build_cplus_array_type (const_ptr_type_node, type);
6990 /* Now, build the VTT object itself. */
6991 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
6992 initialize_artificial_var (vtt, inits);
6993 /* Add the VTT to the vtables list. */
6994 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6995 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6997 dump_vtt (t, vtt);
7000 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7001 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7002 and CHAIN the vtable pointer for this binfo after construction is
7003 complete. VALUE can also be another BINFO, in which case we recurse. */
7005 static tree
7006 binfo_ctor_vtable (tree binfo)
7008 tree vt;
7010 while (1)
7012 vt = BINFO_VTABLE (binfo);
7013 if (TREE_CODE (vt) == TREE_LIST)
7014 vt = TREE_VALUE (vt);
7015 if (TREE_CODE (vt) == TREE_BINFO)
7016 binfo = vt;
7017 else
7018 break;
7021 return vt;
7024 /* Data for secondary VTT initialization. */
7025 typedef struct secondary_vptr_vtt_init_data_s
7027 /* Is this the primary VTT? */
7028 bool top_level_p;
7030 /* Current index into the VTT. */
7031 tree index;
7033 /* TREE_LIST of initializers built up. */
7034 tree inits;
7036 /* The type being constructed by this secondary VTT. */
7037 tree type_being_constructed;
7038 } secondary_vptr_vtt_init_data;
7040 /* Recursively build the VTT-initializer for BINFO (which is in the
7041 hierarchy dominated by T). INITS points to the end of the initializer
7042 list to date. INDEX is the VTT index where the next element will be
7043 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7044 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7045 for virtual bases of T. When it is not so, we build the constructor
7046 vtables for the BINFO-in-T variant. */
7048 static tree *
7049 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
7051 int i;
7052 tree b;
7053 tree init;
7054 tree secondary_vptrs;
7055 secondary_vptr_vtt_init_data data;
7056 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7058 /* We only need VTTs for subobjects with virtual bases. */
7059 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7060 return inits;
7062 /* We need to use a construction vtable if this is not the primary
7063 VTT. */
7064 if (!top_level_p)
7066 build_ctor_vtbl_group (binfo, t);
7068 /* Record the offset in the VTT where this sub-VTT can be found. */
7069 BINFO_SUBVTT_INDEX (binfo) = *index;
7072 /* Add the address of the primary vtable for the complete object. */
7073 init = binfo_ctor_vtable (binfo);
7074 *inits = build_tree_list (NULL_TREE, init);
7075 inits = &TREE_CHAIN (*inits);
7076 if (top_level_p)
7078 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7079 BINFO_VPTR_INDEX (binfo) = *index;
7081 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
7083 /* Recursively add the secondary VTTs for non-virtual bases. */
7084 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
7085 if (!BINFO_VIRTUAL_P (b))
7086 inits = build_vtt_inits (b, t, inits, index);
7088 /* Add secondary virtual pointers for all subobjects of BINFO with
7089 either virtual bases or reachable along a virtual path, except
7090 subobjects that are non-virtual primary bases. */
7091 data.top_level_p = top_level_p;
7092 data.index = *index;
7093 data.inits = NULL;
7094 data.type_being_constructed = BINFO_TYPE (binfo);
7096 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
7098 *index = data.index;
7100 /* The secondary vptrs come back in reverse order. After we reverse
7101 them, and add the INITS, the last init will be the first element
7102 of the chain. */
7103 secondary_vptrs = data.inits;
7104 if (secondary_vptrs)
7106 *inits = nreverse (secondary_vptrs);
7107 inits = &TREE_CHAIN (secondary_vptrs);
7108 gcc_assert (*inits == NULL_TREE);
7111 if (top_level_p)
7112 /* Add the secondary VTTs for virtual bases in inheritance graph
7113 order. */
7114 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
7116 if (!BINFO_VIRTUAL_P (b))
7117 continue;
7119 inits = build_vtt_inits (b, t, inits, index);
7121 else
7122 /* Remove the ctor vtables we created. */
7123 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
7125 return inits;
7128 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7129 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7131 static tree
7132 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
7134 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
7136 /* We don't care about bases that don't have vtables. */
7137 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
7138 return dfs_skip_bases;
7140 /* We're only interested in proper subobjects of the type being
7141 constructed. */
7142 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
7143 return NULL_TREE;
7145 /* We're only interested in bases with virtual bases or reachable
7146 via a virtual path from the type being constructed. */
7147 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7148 || binfo_via_virtual (binfo, data->type_being_constructed)))
7149 return dfs_skip_bases;
7151 /* We're not interested in non-virtual primary bases. */
7152 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
7153 return NULL_TREE;
7155 /* Record the index where this secondary vptr can be found. */
7156 if (data->top_level_p)
7158 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7159 BINFO_VPTR_INDEX (binfo) = data->index;
7161 if (BINFO_VIRTUAL_P (binfo))
7163 /* It's a primary virtual base, and this is not a
7164 construction vtable. Find the base this is primary of in
7165 the inheritance graph, and use that base's vtable
7166 now. */
7167 while (BINFO_PRIMARY_P (binfo))
7168 binfo = BINFO_INHERITANCE_CHAIN (binfo);
7172 /* Add the initializer for the secondary vptr itself. */
7173 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
7175 /* Advance the vtt index. */
7176 data->index = size_binop (PLUS_EXPR, data->index,
7177 TYPE_SIZE_UNIT (ptr_type_node));
7179 return NULL_TREE;
7182 /* Called from build_vtt_inits via dfs_walk. After building
7183 constructor vtables and generating the sub-vtt from them, we need
7184 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7185 binfo of the base whose sub vtt was generated. */
7187 static tree
7188 dfs_fixup_binfo_vtbls (tree binfo, void* data)
7190 tree vtable = BINFO_VTABLE (binfo);
7192 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7193 /* If this class has no vtable, none of its bases do. */
7194 return dfs_skip_bases;
7196 if (!vtable)
7197 /* This might be a primary base, so have no vtable in this
7198 hierarchy. */
7199 return NULL_TREE;
7201 /* If we scribbled the construction vtable vptr into BINFO, clear it
7202 out now. */
7203 if (TREE_CODE (vtable) == TREE_LIST
7204 && (TREE_PURPOSE (vtable) == (tree) data))
7205 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
7207 return NULL_TREE;
7210 /* Build the construction vtable group for BINFO which is in the
7211 hierarchy dominated by T. */
7213 static void
7214 build_ctor_vtbl_group (tree binfo, tree t)
7216 tree list;
7217 tree type;
7218 tree vtbl;
7219 tree inits;
7220 tree id;
7221 tree vbase;
7223 /* See if we've already created this construction vtable group. */
7224 id = mangle_ctor_vtbl_for_type (t, binfo);
7225 if (IDENTIFIER_GLOBAL_VALUE (id))
7226 return;
7228 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
7229 /* Build a version of VTBL (with the wrong type) for use in
7230 constructing the addresses of secondary vtables in the
7231 construction vtable group. */
7232 vtbl = build_vtable (t, id, ptr_type_node);
7233 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
7234 list = build_tree_list (vtbl, NULL_TREE);
7235 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
7236 binfo, t, list);
7238 /* Add the vtables for each of our virtual bases using the vbase in T
7239 binfo. */
7240 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7241 vbase;
7242 vbase = TREE_CHAIN (vbase))
7244 tree b;
7246 if (!BINFO_VIRTUAL_P (vbase))
7247 continue;
7248 b = copied_binfo (vbase, binfo);
7250 accumulate_vtbl_inits (b, vbase, binfo, t, list);
7252 inits = TREE_VALUE (list);
7254 /* Figure out the type of the construction vtable. */
7255 type = build_index_type (size_int (list_length (inits) - 1));
7256 type = build_cplus_array_type (vtable_entry_type, type);
7257 layout_type (type);
7258 TREE_TYPE (vtbl) = type;
7259 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE;
7260 layout_decl (vtbl, 0);
7262 /* Initialize the construction vtable. */
7263 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
7264 initialize_artificial_var (vtbl, inits);
7265 dump_vtable (t, binfo, vtbl);
7268 /* Add the vtbl initializers for BINFO (and its bases other than
7269 non-virtual primaries) to the list of INITS. BINFO is in the
7270 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7271 the constructor the vtbl inits should be accumulated for. (If this
7272 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7273 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7274 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7275 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7276 but are not necessarily the same in terms of layout. */
7278 static void
7279 accumulate_vtbl_inits (tree binfo,
7280 tree orig_binfo,
7281 tree rtti_binfo,
7282 tree t,
7283 tree inits)
7285 int i;
7286 tree base_binfo;
7287 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7289 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7291 /* If it doesn't have a vptr, we don't do anything. */
7292 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7293 return;
7295 /* If we're building a construction vtable, we're not interested in
7296 subobjects that don't require construction vtables. */
7297 if (ctor_vtbl_p
7298 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7299 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7300 return;
7302 /* Build the initializers for the BINFO-in-T vtable. */
7303 TREE_VALUE (inits)
7304 = chainon (TREE_VALUE (inits),
7305 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7306 rtti_binfo, t, inits));
7308 /* Walk the BINFO and its bases. We walk in preorder so that as we
7309 initialize each vtable we can figure out at what offset the
7310 secondary vtable lies from the primary vtable. We can't use
7311 dfs_walk here because we need to iterate through bases of BINFO
7312 and RTTI_BINFO simultaneously. */
7313 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7315 /* Skip virtual bases. */
7316 if (BINFO_VIRTUAL_P (base_binfo))
7317 continue;
7318 accumulate_vtbl_inits (base_binfo,
7319 BINFO_BASE_BINFO (orig_binfo, i),
7320 rtti_binfo, t,
7321 inits);
7325 /* Called from accumulate_vtbl_inits. Returns the initializers for
7326 the BINFO vtable. */
7328 static tree
7329 dfs_accumulate_vtbl_inits (tree binfo,
7330 tree orig_binfo,
7331 tree rtti_binfo,
7332 tree t,
7333 tree l)
7335 tree inits = NULL_TREE;
7336 tree vtbl = NULL_TREE;
7337 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7339 if (ctor_vtbl_p
7340 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7342 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7343 primary virtual base. If it is not the same primary in
7344 the hierarchy of T, we'll need to generate a ctor vtable
7345 for it, to place at its location in T. If it is the same
7346 primary, we still need a VTT entry for the vtable, but it
7347 should point to the ctor vtable for the base it is a
7348 primary for within the sub-hierarchy of RTTI_BINFO.
7350 There are three possible cases:
7352 1) We are in the same place.
7353 2) We are a primary base within a lost primary virtual base of
7354 RTTI_BINFO.
7355 3) We are primary to something not a base of RTTI_BINFO. */
7357 tree b;
7358 tree last = NULL_TREE;
7360 /* First, look through the bases we are primary to for RTTI_BINFO
7361 or a virtual base. */
7362 b = binfo;
7363 while (BINFO_PRIMARY_P (b))
7365 b = BINFO_INHERITANCE_CHAIN (b);
7366 last = b;
7367 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7368 goto found;
7370 /* If we run out of primary links, keep looking down our
7371 inheritance chain; we might be an indirect primary. */
7372 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7373 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7374 break;
7375 found:
7377 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7378 base B and it is a base of RTTI_BINFO, this is case 2. In
7379 either case, we share our vtable with LAST, i.e. the
7380 derived-most base within B of which we are a primary. */
7381 if (b == rtti_binfo
7382 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7383 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7384 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7385 binfo_ctor_vtable after everything's been set up. */
7386 vtbl = last;
7388 /* Otherwise, this is case 3 and we get our own. */
7390 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7391 return inits;
7393 if (!vtbl)
7395 tree index;
7396 int non_fn_entries;
7398 /* Compute the initializer for this vtable. */
7399 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7400 &non_fn_entries);
7402 /* Figure out the position to which the VPTR should point. */
7403 vtbl = TREE_PURPOSE (l);
7404 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7405 index = size_binop (PLUS_EXPR,
7406 size_int (non_fn_entries),
7407 size_int (list_length (TREE_VALUE (l))));
7408 index = size_binop (MULT_EXPR,
7409 TYPE_SIZE_UNIT (vtable_entry_type),
7410 index);
7411 vtbl = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7414 if (ctor_vtbl_p)
7415 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7416 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7417 straighten this out. */
7418 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7419 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7420 inits = NULL_TREE;
7421 else
7422 /* For an ordinary vtable, set BINFO_VTABLE. */
7423 BINFO_VTABLE (binfo) = vtbl;
7425 return inits;
7428 static GTY(()) tree abort_fndecl_addr;
7430 /* Construct the initializer for BINFO's virtual function table. BINFO
7431 is part of the hierarchy dominated by T. If we're building a
7432 construction vtable, the ORIG_BINFO is the binfo we should use to
7433 find the actual function pointers to put in the vtable - but they
7434 can be overridden on the path to most-derived in the graph that
7435 ORIG_BINFO belongs. Otherwise,
7436 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7437 BINFO that should be indicated by the RTTI information in the
7438 vtable; it will be a base class of T, rather than T itself, if we
7439 are building a construction vtable.
7441 The value returned is a TREE_LIST suitable for wrapping in a
7442 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7443 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7444 number of non-function entries in the vtable.
7446 It might seem that this function should never be called with a
7447 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7448 base is always subsumed by a derived class vtable. However, when
7449 we are building construction vtables, we do build vtables for
7450 primary bases; we need these while the primary base is being
7451 constructed. */
7453 static tree
7454 build_vtbl_initializer (tree binfo,
7455 tree orig_binfo,
7456 tree t,
7457 tree rtti_binfo,
7458 int* non_fn_entries_p)
7460 tree v, b;
7461 tree vfun_inits;
7462 vtbl_init_data vid;
7463 unsigned ix;
7464 tree vbinfo;
7465 VEC(tree,gc) *vbases;
7467 /* Initialize VID. */
7468 memset (&vid, 0, sizeof (vid));
7469 vid.binfo = binfo;
7470 vid.derived = t;
7471 vid.rtti_binfo = rtti_binfo;
7472 vid.last_init = &vid.inits;
7473 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7474 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7475 vid.generate_vcall_entries = true;
7476 /* The first vbase or vcall offset is at index -3 in the vtable. */
7477 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7479 /* Add entries to the vtable for RTTI. */
7480 build_rtti_vtbl_entries (binfo, &vid);
7482 /* Create an array for keeping track of the functions we've
7483 processed. When we see multiple functions with the same
7484 signature, we share the vcall offsets. */
7485 vid.fns = VEC_alloc (tree, gc, 32);
7486 /* Add the vcall and vbase offset entries. */
7487 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7489 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7490 build_vbase_offset_vtbl_entries. */
7491 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7492 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7493 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7495 /* If the target requires padding between data entries, add that now. */
7496 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7498 tree cur, *prev;
7500 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7502 tree add = cur;
7503 int i;
7505 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7506 add = tree_cons (NULL_TREE,
7507 build1 (NOP_EXPR, vtable_entry_type,
7508 null_pointer_node),
7509 add);
7510 *prev = add;
7514 if (non_fn_entries_p)
7515 *non_fn_entries_p = list_length (vid.inits);
7517 /* Go through all the ordinary virtual functions, building up
7518 initializers. */
7519 vfun_inits = NULL_TREE;
7520 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7522 tree delta;
7523 tree vcall_index;
7524 tree fn, fn_original;
7525 tree init = NULL_TREE;
7527 fn = BV_FN (v);
7528 fn_original = fn;
7529 if (DECL_THUNK_P (fn))
7531 if (!DECL_NAME (fn))
7532 finish_thunk (fn);
7533 if (THUNK_ALIAS (fn))
7535 fn = THUNK_ALIAS (fn);
7536 BV_FN (v) = fn;
7538 fn_original = THUNK_TARGET (fn);
7541 /* If the only definition of this function signature along our
7542 primary base chain is from a lost primary, this vtable slot will
7543 never be used, so just zero it out. This is important to avoid
7544 requiring extra thunks which cannot be generated with the function.
7546 We first check this in update_vtable_entry_for_fn, so we handle
7547 restored primary bases properly; we also need to do it here so we
7548 zero out unused slots in ctor vtables, rather than filling them
7549 with erroneous values (though harmless, apart from relocation
7550 costs). */
7551 for (b = binfo; ; b = get_primary_binfo (b))
7553 /* We found a defn before a lost primary; go ahead as normal. */
7554 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7555 break;
7557 /* The nearest definition is from a lost primary; clear the
7558 slot. */
7559 if (BINFO_LOST_PRIMARY_P (b))
7561 init = size_zero_node;
7562 break;
7566 if (! init)
7568 /* Pull the offset for `this', and the function to call, out of
7569 the list. */
7570 delta = BV_DELTA (v);
7571 vcall_index = BV_VCALL_INDEX (v);
7573 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7574 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7576 /* You can't call an abstract virtual function; it's abstract.
7577 So, we replace these functions with __pure_virtual. */
7578 if (DECL_PURE_VIRTUAL_P (fn_original))
7580 fn = abort_fndecl;
7581 if (abort_fndecl_addr == NULL)
7582 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7583 init = abort_fndecl_addr;
7585 else
7587 if (!integer_zerop (delta) || vcall_index)
7589 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7590 if (!DECL_NAME (fn))
7591 finish_thunk (fn);
7593 /* Take the address of the function, considering it to be of an
7594 appropriate generic type. */
7595 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7599 /* And add it to the chain of initializers. */
7600 if (TARGET_VTABLE_USES_DESCRIPTORS)
7602 int i;
7603 if (init == size_zero_node)
7604 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7605 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7606 else
7607 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7609 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7610 TREE_OPERAND (init, 0),
7611 build_int_cst (NULL_TREE, i));
7612 TREE_CONSTANT (fdesc) = 1;
7614 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7617 else
7618 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7621 /* The initializers for virtual functions were built up in reverse
7622 order; straighten them out now. */
7623 vfun_inits = nreverse (vfun_inits);
7625 /* The negative offset initializers are also in reverse order. */
7626 vid.inits = nreverse (vid.inits);
7628 /* Chain the two together. */
7629 return chainon (vid.inits, vfun_inits);
7632 /* Adds to vid->inits the initializers for the vbase and vcall
7633 offsets in BINFO, which is in the hierarchy dominated by T. */
7635 static void
7636 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7638 tree b;
7640 /* If this is a derived class, we must first create entries
7641 corresponding to the primary base class. */
7642 b = get_primary_binfo (binfo);
7643 if (b)
7644 build_vcall_and_vbase_vtbl_entries (b, vid);
7646 /* Add the vbase entries for this base. */
7647 build_vbase_offset_vtbl_entries (binfo, vid);
7648 /* Add the vcall entries for this base. */
7649 build_vcall_offset_vtbl_entries (binfo, vid);
7652 /* Returns the initializers for the vbase offset entries in the vtable
7653 for BINFO (which is part of the class hierarchy dominated by T), in
7654 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7655 where the next vbase offset will go. */
7657 static void
7658 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7660 tree vbase;
7661 tree t;
7662 tree non_primary_binfo;
7664 /* If there are no virtual baseclasses, then there is nothing to
7665 do. */
7666 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7667 return;
7669 t = vid->derived;
7671 /* We might be a primary base class. Go up the inheritance hierarchy
7672 until we find the most derived class of which we are a primary base:
7673 it is the offset of that which we need to use. */
7674 non_primary_binfo = binfo;
7675 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7677 tree b;
7679 /* If we have reached a virtual base, then it must be a primary
7680 base (possibly multi-level) of vid->binfo, or we wouldn't
7681 have called build_vcall_and_vbase_vtbl_entries for it. But it
7682 might be a lost primary, so just skip down to vid->binfo. */
7683 if (BINFO_VIRTUAL_P (non_primary_binfo))
7685 non_primary_binfo = vid->binfo;
7686 break;
7689 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7690 if (get_primary_binfo (b) != non_primary_binfo)
7691 break;
7692 non_primary_binfo = b;
7695 /* Go through the virtual bases, adding the offsets. */
7696 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7697 vbase;
7698 vbase = TREE_CHAIN (vbase))
7700 tree b;
7701 tree delta;
7703 if (!BINFO_VIRTUAL_P (vbase))
7704 continue;
7706 /* Find the instance of this virtual base in the complete
7707 object. */
7708 b = copied_binfo (vbase, binfo);
7710 /* If we've already got an offset for this virtual base, we
7711 don't need another one. */
7712 if (BINFO_VTABLE_PATH_MARKED (b))
7713 continue;
7714 BINFO_VTABLE_PATH_MARKED (b) = 1;
7716 /* Figure out where we can find this vbase offset. */
7717 delta = size_binop (MULT_EXPR,
7718 vid->index,
7719 convert (ssizetype,
7720 TYPE_SIZE_UNIT (vtable_entry_type)));
7721 if (vid->primary_vtbl_p)
7722 BINFO_VPTR_FIELD (b) = delta;
7724 if (binfo != TYPE_BINFO (t))
7725 /* The vbase offset had better be the same. */
7726 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7728 /* The next vbase will come at a more negative offset. */
7729 vid->index = size_binop (MINUS_EXPR, vid->index,
7730 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7732 /* The initializer is the delta from BINFO to this virtual base.
7733 The vbase offsets go in reverse inheritance-graph order, and
7734 we are walking in inheritance graph order so these end up in
7735 the right order. */
7736 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7738 *vid->last_init
7739 = build_tree_list (NULL_TREE,
7740 fold_build1 (NOP_EXPR,
7741 vtable_entry_type,
7742 delta));
7743 vid->last_init = &TREE_CHAIN (*vid->last_init);
7747 /* Adds the initializers for the vcall offset entries in the vtable
7748 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7749 to VID->INITS. */
7751 static void
7752 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7754 /* We only need these entries if this base is a virtual base. We
7755 compute the indices -- but do not add to the vtable -- when
7756 building the main vtable for a class. */
7757 if (binfo == TYPE_BINFO (vid->derived)
7758 || (BINFO_VIRTUAL_P (binfo)
7759 /* If BINFO is RTTI_BINFO, then (since BINFO does not
7760 correspond to VID->DERIVED), we are building a primary
7761 construction virtual table. Since this is a primary
7762 virtual table, we do not need the vcall offsets for
7763 BINFO. */
7764 && binfo != vid->rtti_binfo))
7766 /* We need a vcall offset for each of the virtual functions in this
7767 vtable. For example:
7769 class A { virtual void f (); };
7770 class B1 : virtual public A { virtual void f (); };
7771 class B2 : virtual public A { virtual void f (); };
7772 class C: public B1, public B2 { virtual void f (); };
7774 A C object has a primary base of B1, which has a primary base of A. A
7775 C also has a secondary base of B2, which no longer has a primary base
7776 of A. So the B2-in-C construction vtable needs a secondary vtable for
7777 A, which will adjust the A* to a B2* to call f. We have no way of
7778 knowing what (or even whether) this offset will be when we define B2,
7779 so we store this "vcall offset" in the A sub-vtable and look it up in
7780 a "virtual thunk" for B2::f.
7782 We need entries for all the functions in our primary vtable and
7783 in our non-virtual bases' secondary vtables. */
7784 vid->vbase = binfo;
7785 /* If we are just computing the vcall indices -- but do not need
7786 the actual entries -- not that. */
7787 if (!BINFO_VIRTUAL_P (binfo))
7788 vid->generate_vcall_entries = false;
7789 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7790 add_vcall_offset_vtbl_entries_r (binfo, vid);
7794 /* Build vcall offsets, starting with those for BINFO. */
7796 static void
7797 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7799 int i;
7800 tree primary_binfo;
7801 tree base_binfo;
7803 /* Don't walk into virtual bases -- except, of course, for the
7804 virtual base for which we are building vcall offsets. Any
7805 primary virtual base will have already had its offsets generated
7806 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7807 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7808 return;
7810 /* If BINFO has a primary base, process it first. */
7811 primary_binfo = get_primary_binfo (binfo);
7812 if (primary_binfo)
7813 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7815 /* Add BINFO itself to the list. */
7816 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7818 /* Scan the non-primary bases of BINFO. */
7819 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7820 if (base_binfo != primary_binfo)
7821 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7824 /* Called from build_vcall_offset_vtbl_entries_r. */
7826 static void
7827 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7829 /* Make entries for the rest of the virtuals. */
7830 if (abi_version_at_least (2))
7832 tree orig_fn;
7834 /* The ABI requires that the methods be processed in declaration
7835 order. G++ 3.2 used the order in the vtable. */
7836 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7837 orig_fn;
7838 orig_fn = TREE_CHAIN (orig_fn))
7839 if (DECL_VINDEX (orig_fn))
7840 add_vcall_offset (orig_fn, binfo, vid);
7842 else
7844 tree derived_virtuals;
7845 tree base_virtuals;
7846 tree orig_virtuals;
7847 /* If BINFO is a primary base, the most derived class which has
7848 BINFO as a primary base; otherwise, just BINFO. */
7849 tree non_primary_binfo;
7851 /* We might be a primary base class. Go up the inheritance hierarchy
7852 until we find the most derived class of which we are a primary base:
7853 it is the BINFO_VIRTUALS there that we need to consider. */
7854 non_primary_binfo = binfo;
7855 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7857 tree b;
7859 /* If we have reached a virtual base, then it must be vid->vbase,
7860 because we ignore other virtual bases in
7861 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7862 base (possibly multi-level) of vid->binfo, or we wouldn't
7863 have called build_vcall_and_vbase_vtbl_entries for it. But it
7864 might be a lost primary, so just skip down to vid->binfo. */
7865 if (BINFO_VIRTUAL_P (non_primary_binfo))
7867 gcc_assert (non_primary_binfo == vid->vbase);
7868 non_primary_binfo = vid->binfo;
7869 break;
7872 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7873 if (get_primary_binfo (b) != non_primary_binfo)
7874 break;
7875 non_primary_binfo = b;
7878 if (vid->ctor_vtbl_p)
7879 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7880 where rtti_binfo is the most derived type. */
7881 non_primary_binfo
7882 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7884 for (base_virtuals = BINFO_VIRTUALS (binfo),
7885 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7886 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7887 base_virtuals;
7888 base_virtuals = TREE_CHAIN (base_virtuals),
7889 derived_virtuals = TREE_CHAIN (derived_virtuals),
7890 orig_virtuals = TREE_CHAIN (orig_virtuals))
7892 tree orig_fn;
7894 /* Find the declaration that originally caused this function to
7895 be present in BINFO_TYPE (binfo). */
7896 orig_fn = BV_FN (orig_virtuals);
7898 /* When processing BINFO, we only want to generate vcall slots for
7899 function slots introduced in BINFO. So don't try to generate
7900 one if the function isn't even defined in BINFO. */
7901 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7902 continue;
7904 add_vcall_offset (orig_fn, binfo, vid);
7909 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7911 static void
7912 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7914 size_t i;
7915 tree vcall_offset;
7916 tree derived_entry;
7918 /* If there is already an entry for a function with the same
7919 signature as FN, then we do not need a second vcall offset.
7920 Check the list of functions already present in the derived
7921 class vtable. */
7922 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7924 if (same_signature_p (derived_entry, orig_fn)
7925 /* We only use one vcall offset for virtual destructors,
7926 even though there are two virtual table entries. */
7927 || (DECL_DESTRUCTOR_P (derived_entry)
7928 && DECL_DESTRUCTOR_P (orig_fn)))
7929 return;
7932 /* If we are building these vcall offsets as part of building
7933 the vtable for the most derived class, remember the vcall
7934 offset. */
7935 if (vid->binfo == TYPE_BINFO (vid->derived))
7937 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7938 CLASSTYPE_VCALL_INDICES (vid->derived),
7939 NULL);
7940 elt->purpose = orig_fn;
7941 elt->value = vid->index;
7944 /* The next vcall offset will be found at a more negative
7945 offset. */
7946 vid->index = size_binop (MINUS_EXPR, vid->index,
7947 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7949 /* Keep track of this function. */
7950 VEC_safe_push (tree, gc, vid->fns, orig_fn);
7952 if (vid->generate_vcall_entries)
7954 tree base;
7955 tree fn;
7957 /* Find the overriding function. */
7958 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7959 if (fn == error_mark_node)
7960 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7961 integer_zero_node);
7962 else
7964 base = TREE_VALUE (fn);
7966 /* The vbase we're working on is a primary base of
7967 vid->binfo. But it might be a lost primary, so its
7968 BINFO_OFFSET might be wrong, so we just use the
7969 BINFO_OFFSET from vid->binfo. */
7970 vcall_offset = size_diffop (BINFO_OFFSET (base),
7971 BINFO_OFFSET (vid->binfo));
7972 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7973 vcall_offset);
7975 /* Add the initializer to the vtable. */
7976 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7977 vid->last_init = &TREE_CHAIN (*vid->last_init);
7981 /* Return vtbl initializers for the RTTI entries corresponding to the
7982 BINFO's vtable. The RTTI entries should indicate the object given
7983 by VID->rtti_binfo. */
7985 static void
7986 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7988 tree b;
7989 tree t;
7990 tree basetype;
7991 tree offset;
7992 tree decl;
7993 tree init;
7995 basetype = BINFO_TYPE (binfo);
7996 t = BINFO_TYPE (vid->rtti_binfo);
7998 /* To find the complete object, we will first convert to our most
7999 primary base, and then add the offset in the vtbl to that value. */
8000 b = binfo;
8001 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
8002 && !BINFO_LOST_PRIMARY_P (b))
8004 tree primary_base;
8006 primary_base = get_primary_binfo (b);
8007 gcc_assert (BINFO_PRIMARY_P (primary_base)
8008 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
8009 b = primary_base;
8011 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
8013 /* The second entry is the address of the typeinfo object. */
8014 if (flag_rtti)
8015 decl = build_address (get_tinfo_decl (t));
8016 else
8017 decl = integer_zero_node;
8019 /* Convert the declaration to a type that can be stored in the
8020 vtable. */
8021 init = build_nop (vfunc_ptr_type_node, decl);
8022 *vid->last_init = build_tree_list (NULL_TREE, init);
8023 vid->last_init = &TREE_CHAIN (*vid->last_init);
8025 /* Add the offset-to-top entry. It comes earlier in the vtable than
8026 the typeinfo entry. Convert the offset to look like a
8027 function pointer, so that we can put it in the vtable. */
8028 init = build_nop (vfunc_ptr_type_node, offset);
8029 *vid->last_init = build_tree_list (NULL_TREE, init);
8030 vid->last_init = &TREE_CHAIN (*vid->last_init);
8033 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8034 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8036 tree
8037 cp_fold_obj_type_ref (tree ref, tree known_type)
8039 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
8040 HOST_WIDE_INT i = 0;
8041 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
8042 tree fndecl;
8044 while (i != index)
8046 i += (TARGET_VTABLE_USES_DESCRIPTORS
8047 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
8048 v = TREE_CHAIN (v);
8051 fndecl = BV_FN (v);
8053 #ifdef ENABLE_CHECKING
8054 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
8055 DECL_VINDEX (fndecl)));
8056 #endif
8058 cgraph_node (fndecl)->local.vtable_method = true;
8060 return build_address (fndecl);
8063 #include "gt-cp-class.h"