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)
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. */
28 #include "coretypes.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. */
54 /* The _TYPE node for the class. */
57 /* The access specifier pending for new declarations in the scope of
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
67 }* class_stack_node_t;
69 typedef struct vtbl_init_data_s
71 /* The base for which we're building initializers. */
73 /* The type of the most-derived type. */
75 /* The binfo for the dynamic type. This will be TYPE_BINFO (derived),
76 unless ctor_vtbl_p is true. */
78 /* The negative-index vtable initializers built up so far. These
79 are in order from least negative index to most negative index. */
81 /* The last (i.e., most negative) entry in INITS. */
83 /* The binfo for the virtual base for which we're building
84 vcall offset initializers. */
86 /* The functions in vbase for which we have already provided vcall
89 /* The vtable index of the next vcall or vbase offset. */
91 /* Nonzero if we are building the initializer for the primary
94 /* Nonzero if we are building the initializer for a construction
97 /* True when adding vcall offset entries to the vtable. False when
98 merely computing the indices. */
99 bool generate_vcall_entries;
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 propagate_binfo_offsets (tree, tree);
155 static void layout_virtual_bases (record_layout_info, splay_tree);
156 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
157 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
158 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
159 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
160 static void add_vcall_offset (tree, tree, vtbl_init_data *);
161 static void layout_vtable_decl (tree, int);
162 static tree dfs_find_final_overrider_pre (tree, void *);
163 static tree dfs_find_final_overrider_post (tree, void *);
164 static tree find_final_overrider (tree, tree, tree);
165 static int make_new_vtable (tree, tree);
166 static tree get_primary_binfo (tree);
167 static int maybe_indent_hierarchy (FILE *, int, int);
168 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
169 static void dump_class_hierarchy (tree);
170 static void dump_class_hierarchy_1 (FILE *, int, tree);
171 static void dump_array (FILE *, tree);
172 static void dump_vtable (tree, tree, tree);
173 static void dump_vtt (tree, tree);
174 static void dump_thunk (FILE *, int, tree);
175 static tree build_vtable (tree, tree, tree);
176 static void initialize_vtable (tree, tree);
177 static void layout_nonempty_base_or_field (record_layout_info,
178 tree, tree, splay_tree);
179 static tree end_of_class (tree, int);
180 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree);
181 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
182 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
184 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
185 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
186 static void clone_constructors_and_destructors (tree);
187 static tree build_clone (tree, tree);
188 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
189 static void build_ctor_vtbl_group (tree, tree);
190 static void build_vtt (tree);
191 static tree binfo_ctor_vtable (tree);
192 static tree *build_vtt_inits (tree, tree, tree *, tree *);
193 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
194 static tree dfs_fixup_binfo_vtbls (tree, void *);
195 static int record_subobject_offset (tree, tree, splay_tree);
196 static int check_subobject_offset (tree, tree, splay_tree);
197 static int walk_subobject_offsets (tree, subobject_offset_fn,
198 tree, splay_tree, tree, int);
199 static void record_subobject_offsets (tree, tree, splay_tree, bool);
200 static int layout_conflict_p (tree, tree, splay_tree, int);
201 static int splay_tree_compare_integer_csts (splay_tree_key k1,
203 static void warn_about_ambiguous_bases (tree);
204 static bool type_requires_array_cookie (tree);
205 static bool contains_empty_class_p (tree);
206 static bool base_derived_from (tree, tree);
207 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
208 static tree end_of_base (tree);
209 static tree get_vcall_index (tree, tree);
211 /* Variables shared between class.c and call.c. */
213 #ifdef GATHER_STATISTICS
215 int n_vtable_entries = 0;
216 int n_vtable_searches = 0;
217 int n_vtable_elems = 0;
218 int n_convert_harshness = 0;
219 int n_compute_conversion_costs = 0;
220 int n_inner_fields_searched = 0;
223 /* Convert to or from a base subobject. EXPR is an expression of type
224 `A' or `A*', an expression of type `B' or `B*' is returned. To
225 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
226 the B base instance within A. To convert base A to derived B, CODE
227 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
228 In this latter case, A must not be a morally virtual base of B.
229 NONNULL is true if EXPR is known to be non-NULL (this is only
230 needed when EXPR is of pointer type). CV qualifiers are preserved
234 build_base_path (enum tree_code code,
239 tree v_binfo = NULL_TREE;
240 tree d_binfo = NULL_TREE;
244 tree null_test = NULL;
245 tree ptr_target_type;
247 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
248 bool has_empty = false;
251 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
252 return error_mark_node;
254 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
257 if (is_empty_class (BINFO_TYPE (probe)))
259 if (!v_binfo && BINFO_VIRTUAL_P (probe))
263 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
267 gcc_assert ((code == MINUS_EXPR
268 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
269 || (code == PLUS_EXPR
270 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
272 if (binfo == d_binfo)
276 if (code == MINUS_EXPR && v_binfo)
278 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
279 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
280 return error_mark_node;
284 /* This must happen before the call to save_expr. */
285 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error);
287 offset = BINFO_OFFSET (binfo);
288 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
289 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
291 /* Do we need to look in the vtable for the real offset? */
292 virtual_access = (v_binfo && fixed_type_p <= 0);
294 /* Don't bother with the calculations inside sizeof; they'll ICE if the
295 source type is incomplete and the pointer value doesn't matter. */
296 if (cp_unevaluated_operand != 0)
298 expr = build_nop (build_pointer_type (target_type), expr);
300 expr = build_indirect_ref (EXPR_LOCATION (expr), expr, NULL);
304 /* Do we need to check for a null pointer? */
305 if (want_pointer && !nonnull)
307 /* If we know the conversion will not actually change the value
308 of EXPR, then we can avoid testing the expression for NULL.
309 We have to avoid generating a COMPONENT_REF for a base class
310 field, because other parts of the compiler know that such
311 expressions are always non-NULL. */
312 if (!virtual_access && integer_zerop (offset))
315 /* TARGET_TYPE has been extracted from BINFO, and, is
316 therefore always cv-unqualified. Extract the
317 cv-qualifiers from EXPR so that the expression returned
318 matches the input. */
319 class_type = TREE_TYPE (TREE_TYPE (expr));
321 = cp_build_qualified_type (target_type,
322 cp_type_quals (class_type));
323 return build_nop (build_pointer_type (target_type), expr);
325 null_test = error_mark_node;
328 /* Protect against multiple evaluation if necessary. */
329 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
330 expr = save_expr (expr);
332 /* Now that we've saved expr, build the real null test. */
335 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
336 null_test = fold_build2_loc (input_location, NE_EXPR, boolean_type_node,
340 /* If this is a simple base reference, express it as a COMPONENT_REF. */
341 if (code == PLUS_EXPR && !virtual_access
342 /* We don't build base fields for empty bases, and they aren't very
343 interesting to the optimizers anyway. */
346 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
347 expr = build_simple_base_path (expr, binfo);
349 expr = build_address (expr);
350 target_type = TREE_TYPE (expr);
356 /* Going via virtual base V_BINFO. We need the static offset
357 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
358 V_BINFO. That offset is an entry in D_BINFO's vtable. */
361 if (fixed_type_p < 0 && in_base_initializer)
363 /* In a base member initializer, we cannot rely on the
364 vtable being set up. We have to indirect via the
368 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
369 t = build_pointer_type (t);
370 v_offset = convert (t, current_vtt_parm);
371 v_offset = cp_build_indirect_ref (v_offset, NULL,
372 tf_warning_or_error);
375 v_offset = build_vfield_ref (cp_build_indirect_ref (expr, NULL,
376 tf_warning_or_error),
377 TREE_TYPE (TREE_TYPE (expr)));
379 v_offset = build2 (POINTER_PLUS_EXPR, TREE_TYPE (v_offset),
380 v_offset, fold_convert (sizetype, BINFO_VPTR_FIELD (v_binfo)));
381 v_offset = build1 (NOP_EXPR,
382 build_pointer_type (ptrdiff_type_node),
384 v_offset = cp_build_indirect_ref (v_offset, NULL, tf_warning_or_error);
385 TREE_CONSTANT (v_offset) = 1;
387 offset = convert_to_integer (ptrdiff_type_node,
388 size_diffop_loc (input_location, offset,
389 BINFO_OFFSET (v_binfo)));
391 if (!integer_zerop (offset))
392 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
394 if (fixed_type_p < 0)
395 /* Negative fixed_type_p means this is a constructor or destructor;
396 virtual base layout is fixed in in-charge [cd]tors, but not in
398 offset = build3 (COND_EXPR, ptrdiff_type_node,
399 build2 (EQ_EXPR, boolean_type_node,
400 current_in_charge_parm, integer_zero_node),
402 convert_to_integer (ptrdiff_type_node,
403 BINFO_OFFSET (binfo)));
408 target_type = cp_build_qualified_type
409 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
410 ptr_target_type = build_pointer_type (target_type);
412 target_type = ptr_target_type;
414 expr = build1 (NOP_EXPR, ptr_target_type, expr);
416 if (!integer_zerop (offset))
418 offset = fold_convert (sizetype, offset);
419 if (code == MINUS_EXPR)
420 offset = fold_build1_loc (input_location, NEGATE_EXPR, sizetype, offset);
421 expr = build2 (POINTER_PLUS_EXPR, ptr_target_type, expr, offset);
427 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
431 expr = fold_build3_loc (input_location, COND_EXPR, target_type, null_test, expr,
432 fold_build1_loc (input_location, NOP_EXPR, target_type,
438 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
439 Perform a derived-to-base conversion by recursively building up a
440 sequence of COMPONENT_REFs to the appropriate base fields. */
443 build_simple_base_path (tree expr, tree binfo)
445 tree type = BINFO_TYPE (binfo);
446 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
449 if (d_binfo == NULL_TREE)
453 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
455 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
456 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
457 an lvalue in the front end; only _DECLs and _REFs are lvalues
459 temp = unary_complex_lvalue (ADDR_EXPR, expr);
461 expr = cp_build_indirect_ref (temp, NULL, tf_warning_or_error);
467 expr = build_simple_base_path (expr, d_binfo);
469 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
470 field; field = TREE_CHAIN (field))
471 /* Is this the base field created by build_base_field? */
472 if (TREE_CODE (field) == FIELD_DECL
473 && DECL_FIELD_IS_BASE (field)
474 && TREE_TYPE (field) == type)
476 /* We don't use build_class_member_access_expr here, as that
477 has unnecessary checks, and more importantly results in
478 recursive calls to dfs_walk_once. */
479 int type_quals = cp_type_quals (TREE_TYPE (expr));
481 expr = build3 (COMPONENT_REF,
482 cp_build_qualified_type (type, type_quals),
483 expr, field, NULL_TREE);
484 expr = fold_if_not_in_template (expr);
486 /* Mark the expression const or volatile, as appropriate.
487 Even though we've dealt with the type above, we still have
488 to mark the expression itself. */
489 if (type_quals & TYPE_QUAL_CONST)
490 TREE_READONLY (expr) = 1;
491 if (type_quals & TYPE_QUAL_VOLATILE)
492 TREE_THIS_VOLATILE (expr) = 1;
497 /* Didn't find the base field?!? */
501 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
502 type is a class type or a pointer to a class type. In the former
503 case, TYPE is also a class type; in the latter it is another
504 pointer type. If CHECK_ACCESS is true, an error message is emitted
505 if TYPE is inaccessible. If OBJECT has pointer type, the value is
506 assumed to be non-NULL. */
509 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
514 if (TYPE_PTR_P (TREE_TYPE (object)))
516 object_type = TREE_TYPE (TREE_TYPE (object));
517 type = TREE_TYPE (type);
520 object_type = TREE_TYPE (object);
522 binfo = lookup_base (object_type, type,
523 check_access ? ba_check : ba_unique,
525 if (!binfo || binfo == error_mark_node)
526 return error_mark_node;
528 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
531 /* EXPR is an expression with unqualified class type. BASE is a base
532 binfo of that class type. Returns EXPR, converted to the BASE
533 type. This function assumes that EXPR is the most derived class;
534 therefore virtual bases can be found at their static offsets. */
537 convert_to_base_statically (tree expr, tree base)
541 expr_type = TREE_TYPE (expr);
542 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
546 pointer_type = build_pointer_type (expr_type);
548 /* We use fold_build2 and fold_convert below to simplify the trees
549 provided to the optimizers. It is not safe to call these functions
550 when processing a template because they do not handle C++-specific
552 gcc_assert (!processing_template_decl);
553 expr = cp_build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1,
554 tf_warning_or_error);
555 if (!integer_zerop (BINFO_OFFSET (base)))
556 expr = fold_build2_loc (input_location,
557 POINTER_PLUS_EXPR, pointer_type, expr,
558 fold_convert (sizetype, BINFO_OFFSET (base)));
559 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr);
560 expr = build_fold_indirect_ref_loc (input_location, expr);
568 build_vfield_ref (tree datum, tree type)
570 tree vfield, vcontext;
572 if (datum == error_mark_node)
573 return error_mark_node;
575 /* First, convert to the requested type. */
576 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
577 datum = convert_to_base (datum, type, /*check_access=*/false,
580 /* Second, the requested type may not be the owner of its own vptr.
581 If not, convert to the base class that owns it. We cannot use
582 convert_to_base here, because VCONTEXT may appear more than once
583 in the inheritance hierarchy of TYPE, and thus direct conversion
584 between the types may be ambiguous. Following the path back up
585 one step at a time via primary bases avoids the problem. */
586 vfield = TYPE_VFIELD (type);
587 vcontext = DECL_CONTEXT (vfield);
588 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
590 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
591 type = TREE_TYPE (datum);
594 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
597 /* Given an object INSTANCE, return an expression which yields the
598 vtable element corresponding to INDEX. There are many special
599 cases for INSTANCE which we take care of here, mainly to avoid
600 creating extra tree nodes when we don't have to. */
603 build_vtbl_ref_1 (tree instance, tree idx)
606 tree vtbl = NULL_TREE;
608 /* Try to figure out what a reference refers to, and
609 access its virtual function table directly. */
612 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
614 tree basetype = non_reference (TREE_TYPE (instance));
616 if (fixed_type && !cdtorp)
618 tree binfo = lookup_base (fixed_type, basetype,
619 ba_unique | ba_quiet, NULL);
621 vtbl = unshare_expr (BINFO_VTABLE (binfo));
625 vtbl = build_vfield_ref (instance, basetype);
627 aref = build_array_ref (input_location, vtbl, idx);
628 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
634 build_vtbl_ref (tree instance, tree idx)
636 tree aref = build_vtbl_ref_1 (instance, idx);
641 /* Given a stable object pointer INSTANCE_PTR, return an expression which
642 yields a function pointer corresponding to vtable element INDEX. */
645 build_vfn_ref (tree instance_ptr, tree idx)
649 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, 0,
650 tf_warning_or_error),
653 /* When using function descriptors, the address of the
654 vtable entry is treated as a function pointer. */
655 if (TARGET_VTABLE_USES_DESCRIPTORS)
656 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
657 cp_build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1,
658 tf_warning_or_error));
660 /* Remember this as a method reference, for later devirtualization. */
661 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
666 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
667 for the given TYPE. */
670 get_vtable_name (tree type)
672 return mangle_vtbl_for_type (type);
675 /* DECL is an entity associated with TYPE, like a virtual table or an
676 implicitly generated constructor. Determine whether or not DECL
677 should have external or internal linkage at the object file
678 level. This routine does not deal with COMDAT linkage and other
679 similar complexities; it simply sets TREE_PUBLIC if it possible for
680 entities in other translation units to contain copies of DECL, in
684 set_linkage_according_to_type (tree type, tree decl)
686 /* If TYPE involves a local class in a function with internal
687 linkage, then DECL should have internal linkage too. Other local
688 classes have no linkage -- but if their containing functions
689 have external linkage, it makes sense for DECL to have external
690 linkage too. That will allow template definitions to be merged,
692 if (no_linkage_check (type, /*relaxed_p=*/true))
694 TREE_PUBLIC (decl) = 0;
695 DECL_INTERFACE_KNOWN (decl) = 1;
698 TREE_PUBLIC (decl) = 1;
701 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
702 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
703 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
706 build_vtable (tree class_type, tree name, tree vtable_type)
710 decl = build_lang_decl (VAR_DECL, name, vtable_type);
711 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
712 now to avoid confusion in mangle_decl. */
713 SET_DECL_ASSEMBLER_NAME (decl, name);
714 DECL_CONTEXT (decl) = class_type;
715 DECL_ARTIFICIAL (decl) = 1;
716 TREE_STATIC (decl) = 1;
717 TREE_READONLY (decl) = 1;
718 DECL_VIRTUAL_P (decl) = 1;
719 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
720 DECL_VTABLE_OR_VTT_P (decl) = 1;
721 /* At one time the vtable info was grabbed 2 words at a time. This
722 fails on sparc unless you have 8-byte alignment. (tiemann) */
723 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
725 set_linkage_according_to_type (class_type, decl);
726 /* The vtable has not been defined -- yet. */
727 DECL_EXTERNAL (decl) = 1;
728 DECL_NOT_REALLY_EXTERN (decl) = 1;
730 /* Mark the VAR_DECL node representing the vtable itself as a
731 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
732 is rather important that such things be ignored because any
733 effort to actually generate DWARF for them will run into
734 trouble when/if we encounter code like:
737 struct S { virtual void member (); };
739 because the artificial declaration of the vtable itself (as
740 manufactured by the g++ front end) will say that the vtable is
741 a static member of `S' but only *after* the debug output for
742 the definition of `S' has already been output. This causes
743 grief because the DWARF entry for the definition of the vtable
744 will try to refer back to an earlier *declaration* of the
745 vtable as a static member of `S' and there won't be one. We
746 might be able to arrange to have the "vtable static member"
747 attached to the member list for `S' before the debug info for
748 `S' get written (which would solve the problem) but that would
749 require more intrusive changes to the g++ front end. */
750 DECL_IGNORED_P (decl) = 1;
755 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
756 or even complete. If this does not exist, create it. If COMPLETE is
757 nonzero, then complete the definition of it -- that will render it
758 impossible to actually build the vtable, but is useful to get at those
759 which are known to exist in the runtime. */
762 get_vtable_decl (tree type, int complete)
766 if (CLASSTYPE_VTABLES (type))
767 return CLASSTYPE_VTABLES (type);
769 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
770 CLASSTYPE_VTABLES (type) = decl;
774 DECL_EXTERNAL (decl) = 1;
775 cp_finish_decl (decl, NULL_TREE, false, NULL_TREE, 0);
781 /* Build the primary virtual function table for TYPE. If BINFO is
782 non-NULL, build the vtable starting with the initial approximation
783 that it is the same as the one which is the head of the association
784 list. Returns a nonzero value if a new vtable is actually
788 build_primary_vtable (tree binfo, tree type)
793 decl = get_vtable_decl (type, /*complete=*/0);
797 if (BINFO_NEW_VTABLE_MARKED (binfo))
798 /* We have already created a vtable for this base, so there's
799 no need to do it again. */
802 virtuals = copy_list (BINFO_VIRTUALS (binfo));
803 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
804 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
805 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
809 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
810 virtuals = NULL_TREE;
813 #ifdef GATHER_STATISTICS
815 n_vtable_elems += list_length (virtuals);
818 /* Initialize the association list for this type, based
819 on our first approximation. */
820 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
821 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
822 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
826 /* Give BINFO a new virtual function table which is initialized
827 with a skeleton-copy of its original initialization. The only
828 entry that changes is the `delta' entry, so we can really
829 share a lot of structure.
831 FOR_TYPE is the most derived type which caused this table to
834 Returns nonzero if we haven't met BINFO before.
836 The order in which vtables are built (by calling this function) for
837 an object must remain the same, otherwise a binary incompatibility
841 build_secondary_vtable (tree binfo)
843 if (BINFO_NEW_VTABLE_MARKED (binfo))
844 /* We already created a vtable for this base. There's no need to
848 /* Remember that we've created a vtable for this BINFO, so that we
849 don't try to do so again. */
850 SET_BINFO_NEW_VTABLE_MARKED (binfo);
852 /* Make fresh virtual list, so we can smash it later. */
853 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
855 /* Secondary vtables are laid out as part of the same structure as
856 the primary vtable. */
857 BINFO_VTABLE (binfo) = NULL_TREE;
861 /* Create a new vtable for BINFO which is the hierarchy dominated by
862 T. Return nonzero if we actually created a new vtable. */
865 make_new_vtable (tree t, tree binfo)
867 if (binfo == TYPE_BINFO (t))
868 /* In this case, it is *type*'s vtable we are modifying. We start
869 with the approximation that its vtable is that of the
870 immediate base class. */
871 return build_primary_vtable (binfo, t);
873 /* This is our very own copy of `basetype' to play with. Later,
874 we will fill in all the virtual functions that override the
875 virtual functions in these base classes which are not defined
876 by the current type. */
877 return build_secondary_vtable (binfo);
880 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
881 (which is in the hierarchy dominated by T) list FNDECL as its
882 BV_FN. DELTA is the required constant adjustment from the `this'
883 pointer where the vtable entry appears to the `this' required when
884 the function is actually called. */
887 modify_vtable_entry (tree t,
897 if (fndecl != BV_FN (v)
898 || !tree_int_cst_equal (delta, BV_DELTA (v)))
900 /* We need a new vtable for BINFO. */
901 if (make_new_vtable (t, binfo))
903 /* If we really did make a new vtable, we also made a copy
904 of the BINFO_VIRTUALS list. Now, we have to find the
905 corresponding entry in that list. */
906 *virtuals = BINFO_VIRTUALS (binfo);
907 while (BV_FN (*virtuals) != BV_FN (v))
908 *virtuals = TREE_CHAIN (*virtuals);
912 BV_DELTA (v) = delta;
913 BV_VCALL_INDEX (v) = NULL_TREE;
919 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
920 the USING_DECL naming METHOD. Returns true if the method could be
921 added to the method vec. */
924 add_method (tree type, tree method, tree using_decl)
928 bool template_conv_p = false;
930 VEC(tree,gc) *method_vec;
932 bool insert_p = false;
936 if (method == error_mark_node)
939 complete_p = COMPLETE_TYPE_P (type);
940 conv_p = DECL_CONV_FN_P (method);
942 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
943 && DECL_TEMPLATE_CONV_FN_P (method));
945 method_vec = CLASSTYPE_METHOD_VEC (type);
948 /* Make a new method vector. We start with 8 entries. We must
949 allocate at least two (for constructors and destructors), and
950 we're going to end up with an assignment operator at some
952 method_vec = VEC_alloc (tree, gc, 8);
953 /* Create slots for constructors and destructors. */
954 VEC_quick_push (tree, method_vec, NULL_TREE);
955 VEC_quick_push (tree, method_vec, NULL_TREE);
956 CLASSTYPE_METHOD_VEC (type) = method_vec;
959 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
960 grok_special_member_properties (method);
962 /* Constructors and destructors go in special slots. */
963 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
964 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
965 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
967 slot = CLASSTYPE_DESTRUCTOR_SLOT;
969 if (TYPE_FOR_JAVA (type))
971 if (!DECL_ARTIFICIAL (method))
972 error ("Java class %qT cannot have a destructor", type);
973 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
974 error ("Java class %qT cannot have an implicit non-trivial "
984 /* See if we already have an entry with this name. */
985 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
986 VEC_iterate (tree, method_vec, slot, m);
992 if (TREE_CODE (m) == TEMPLATE_DECL
993 && DECL_TEMPLATE_CONV_FN_P (m))
997 if (conv_p && !DECL_CONV_FN_P (m))
999 if (DECL_NAME (m) == DECL_NAME (method))
1005 && !DECL_CONV_FN_P (m)
1006 && DECL_NAME (m) > DECL_NAME (method))
1010 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
1012 /* Check to see if we've already got this method. */
1013 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
1015 tree fn = OVL_CURRENT (fns);
1021 if (TREE_CODE (fn) != TREE_CODE (method))
1024 /* [over.load] Member function declarations with the
1025 same name and the same parameter types cannot be
1026 overloaded if any of them is a static member
1027 function declaration.
1029 [namespace.udecl] When a using-declaration brings names
1030 from a base class into a derived class scope, member
1031 functions in the derived class override and/or hide member
1032 functions with the same name and parameter types in a base
1033 class (rather than conflicting). */
1034 fn_type = TREE_TYPE (fn);
1035 method_type = TREE_TYPE (method);
1036 parms1 = TYPE_ARG_TYPES (fn_type);
1037 parms2 = TYPE_ARG_TYPES (method_type);
1039 /* Compare the quals on the 'this' parm. Don't compare
1040 the whole types, as used functions are treated as
1041 coming from the using class in overload resolution. */
1042 if (! DECL_STATIC_FUNCTION_P (fn)
1043 && ! DECL_STATIC_FUNCTION_P (method)
1044 && TREE_TYPE (TREE_VALUE (parms1)) != error_mark_node
1045 && TREE_TYPE (TREE_VALUE (parms2)) != error_mark_node
1046 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1047 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1050 /* For templates, the return type and template parameters
1051 must be identical. */
1052 if (TREE_CODE (fn) == TEMPLATE_DECL
1053 && (!same_type_p (TREE_TYPE (fn_type),
1054 TREE_TYPE (method_type))
1055 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1056 DECL_TEMPLATE_PARMS (method))))
1059 if (! DECL_STATIC_FUNCTION_P (fn))
1060 parms1 = TREE_CHAIN (parms1);
1061 if (! DECL_STATIC_FUNCTION_P (method))
1062 parms2 = TREE_CHAIN (parms2);
1064 if (compparms (parms1, parms2)
1065 && (!DECL_CONV_FN_P (fn)
1066 || same_type_p (TREE_TYPE (fn_type),
1067 TREE_TYPE (method_type))))
1071 if (DECL_CONTEXT (fn) == type)
1072 /* Defer to the local function. */
1074 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1075 error ("repeated using declaration %q+D", using_decl);
1077 error ("using declaration %q+D conflicts with a previous using declaration",
1082 error ("%q+#D cannot be overloaded", method);
1083 error ("with %q+#D", fn);
1086 /* We don't call duplicate_decls here to merge the
1087 declarations because that will confuse things if the
1088 methods have inline definitions. In particular, we
1089 will crash while processing the definitions. */
1094 /* A class should never have more than one destructor. */
1095 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1098 /* Add the new binding. */
1099 overload = build_overload (method, current_fns);
1102 TYPE_HAS_CONVERSION (type) = 1;
1103 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1104 push_class_level_binding (DECL_NAME (method), overload);
1110 /* We only expect to add few methods in the COMPLETE_P case, so
1111 just make room for one more method in that case. */
1113 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1);
1115 reallocated = VEC_reserve (tree, gc, method_vec, 1);
1117 CLASSTYPE_METHOD_VEC (type) = method_vec;
1118 if (slot == VEC_length (tree, method_vec))
1119 VEC_quick_push (tree, method_vec, overload);
1121 VEC_quick_insert (tree, method_vec, slot, overload);
1124 /* Replace the current slot. */
1125 VEC_replace (tree, method_vec, slot, overload);
1129 /* Subroutines of finish_struct. */
1131 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1132 legit, otherwise return 0. */
1135 alter_access (tree t, tree fdecl, tree access)
1139 if (!DECL_LANG_SPECIFIC (fdecl))
1140 retrofit_lang_decl (fdecl);
1142 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1144 elem = purpose_member (t, DECL_ACCESS (fdecl));
1147 if (TREE_VALUE (elem) != access)
1149 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1150 error ("conflicting access specifications for method"
1151 " %q+D, ignored", TREE_TYPE (fdecl));
1153 error ("conflicting access specifications for field %qE, ignored",
1158 /* They're changing the access to the same thing they changed
1159 it to before. That's OK. */
1165 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl);
1166 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1172 /* Process the USING_DECL, which is a member of T. */
1175 handle_using_decl (tree using_decl, tree t)
1177 tree decl = USING_DECL_DECLS (using_decl);
1178 tree name = DECL_NAME (using_decl);
1180 = TREE_PRIVATE (using_decl) ? access_private_node
1181 : TREE_PROTECTED (using_decl) ? access_protected_node
1182 : access_public_node;
1183 tree flist = NULL_TREE;
1186 gcc_assert (!processing_template_decl && decl);
1188 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1191 if (is_overloaded_fn (old_value))
1192 old_value = OVL_CURRENT (old_value);
1194 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1197 old_value = NULL_TREE;
1200 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1202 if (is_overloaded_fn (decl))
1207 else if (is_overloaded_fn (old_value))
1210 /* It's OK to use functions from a base when there are functions with
1211 the same name already present in the current class. */;
1214 error ("%q+D invalid in %q#T", using_decl, t);
1215 error (" because of local method %q+#D with same name",
1216 OVL_CURRENT (old_value));
1220 else if (!DECL_ARTIFICIAL (old_value))
1222 error ("%q+D invalid in %q#T", using_decl, t);
1223 error (" because of local member %q+#D with same name", old_value);
1227 /* Make type T see field decl FDECL with access ACCESS. */
1229 for (; flist; flist = OVL_NEXT (flist))
1231 add_method (t, OVL_CURRENT (flist), using_decl);
1232 alter_access (t, OVL_CURRENT (flist), access);
1235 alter_access (t, decl, access);
1238 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1239 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1240 properties of the bases. */
1243 check_bases (tree t,
1244 int* cant_have_const_ctor_p,
1245 int* no_const_asn_ref_p)
1248 int seen_non_virtual_nearly_empty_base_p;
1251 tree field = NULL_TREE;
1253 seen_non_virtual_nearly_empty_base_p = 0;
1255 if (!CLASSTYPE_NON_STD_LAYOUT (t))
1256 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
1257 if (TREE_CODE (field) == FIELD_DECL)
1260 for (binfo = TYPE_BINFO (t), i = 0;
1261 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1263 tree basetype = TREE_TYPE (base_binfo);
1265 gcc_assert (COMPLETE_TYPE_P (basetype));
1267 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1268 here because the case of virtual functions but non-virtual
1269 dtor is handled in finish_struct_1. */
1270 if (!TYPE_POLYMORPHIC_P (basetype))
1271 warning (OPT_Weffc__,
1272 "base class %q#T has a non-virtual destructor", basetype);
1274 /* If the base class doesn't have copy constructors or
1275 assignment operators that take const references, then the
1276 derived class cannot have such a member automatically
1278 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1279 *cant_have_const_ctor_p = 1;
1280 if (TYPE_HAS_ASSIGN_REF (basetype)
1281 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1282 *no_const_asn_ref_p = 1;
1284 if (BINFO_VIRTUAL_P (base_binfo))
1285 /* A virtual base does not effect nearly emptiness. */
1287 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1289 if (seen_non_virtual_nearly_empty_base_p)
1290 /* And if there is more than one nearly empty base, then the
1291 derived class is not nearly empty either. */
1292 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1294 /* Remember we've seen one. */
1295 seen_non_virtual_nearly_empty_base_p = 1;
1297 else if (!is_empty_class (basetype))
1298 /* If the base class is not empty or nearly empty, then this
1299 class cannot be nearly empty. */
1300 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1302 /* A lot of properties from the bases also apply to the derived
1304 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1305 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1306 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1307 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1308 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1309 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1310 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1311 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1312 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1313 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (basetype);
1315 /* A standard-layout class is a class that:
1317 * has no non-standard-layout base classes, */
1318 CLASSTYPE_NON_STD_LAYOUT (t) |= CLASSTYPE_NON_STD_LAYOUT (basetype);
1319 if (!CLASSTYPE_NON_STD_LAYOUT (t))
1322 /* ...has no base classes of the same type as the first non-static
1324 if (field && DECL_CONTEXT (field) == t
1325 && (same_type_ignoring_top_level_qualifiers_p
1326 (TREE_TYPE (field), basetype)))
1327 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
1329 /* ...either has no non-static data members in the most-derived
1330 class and at most one base class with non-static data
1331 members, or has no base classes with non-static data
1333 for (basefield = TYPE_FIELDS (basetype); basefield;
1334 basefield = TREE_CHAIN (basefield))
1335 if (TREE_CODE (basefield) == FIELD_DECL)
1338 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
1347 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1348 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1349 that have had a nearly-empty virtual primary base stolen by some
1350 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1354 determine_primary_bases (tree t)
1357 tree primary = NULL_TREE;
1358 tree type_binfo = TYPE_BINFO (t);
1361 /* Determine the primary bases of our bases. */
1362 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1363 base_binfo = TREE_CHAIN (base_binfo))
1365 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1367 /* See if we're the non-virtual primary of our inheritance
1369 if (!BINFO_VIRTUAL_P (base_binfo))
1371 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1372 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1375 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1376 BINFO_TYPE (parent_primary)))
1377 /* We are the primary binfo. */
1378 BINFO_PRIMARY_P (base_binfo) = 1;
1380 /* Determine if we have a virtual primary base, and mark it so.
1382 if (primary && BINFO_VIRTUAL_P (primary))
1384 tree this_primary = copied_binfo (primary, base_binfo);
1386 if (BINFO_PRIMARY_P (this_primary))
1387 /* Someone already claimed this base. */
1388 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1393 BINFO_PRIMARY_P (this_primary) = 1;
1394 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1396 /* A virtual binfo might have been copied from within
1397 another hierarchy. As we're about to use it as a
1398 primary base, make sure the offsets match. */
1399 delta = size_diffop_loc (input_location,
1401 BINFO_OFFSET (base_binfo)),
1403 BINFO_OFFSET (this_primary)));
1405 propagate_binfo_offsets (this_primary, delta);
1410 /* First look for a dynamic direct non-virtual base. */
1411 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1413 tree basetype = BINFO_TYPE (base_binfo);
1415 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1417 primary = base_binfo;
1422 /* A "nearly-empty" virtual base class can be the primary base
1423 class, if no non-virtual polymorphic base can be found. Look for
1424 a nearly-empty virtual dynamic base that is not already a primary
1425 base of something in the hierarchy. If there is no such base,
1426 just pick the first nearly-empty virtual base. */
1428 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1429 base_binfo = TREE_CHAIN (base_binfo))
1430 if (BINFO_VIRTUAL_P (base_binfo)
1431 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1433 if (!BINFO_PRIMARY_P (base_binfo))
1435 /* Found one that is not primary. */
1436 primary = base_binfo;
1440 /* Remember the first candidate. */
1441 primary = base_binfo;
1445 /* If we've got a primary base, use it. */
1448 tree basetype = BINFO_TYPE (primary);
1450 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1451 if (BINFO_PRIMARY_P (primary))
1452 /* We are stealing a primary base. */
1453 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1454 BINFO_PRIMARY_P (primary) = 1;
1455 if (BINFO_VIRTUAL_P (primary))
1459 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1460 /* A virtual binfo might have been copied from within
1461 another hierarchy. As we're about to use it as a primary
1462 base, make sure the offsets match. */
1463 delta = size_diffop_loc (input_location, ssize_int (0),
1464 convert (ssizetype, BINFO_OFFSET (primary)));
1466 propagate_binfo_offsets (primary, delta);
1469 primary = TYPE_BINFO (basetype);
1471 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1472 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1473 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1477 /* Update the variant types of T. */
1480 fixup_type_variants (tree t)
1487 for (variants = TYPE_NEXT_VARIANT (t);
1489 variants = TYPE_NEXT_VARIANT (variants))
1491 /* These fields are in the _TYPE part of the node, not in
1492 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1493 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
1494 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1495 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1496 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1498 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1500 TYPE_BINFO (variants) = TYPE_BINFO (t);
1502 /* Copy whatever these are holding today. */
1503 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1504 TYPE_METHODS (variants) = TYPE_METHODS (t);
1505 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1507 /* All variants of a class have the same attributes. */
1508 TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t);
1513 /* Set memoizing fields and bits of T (and its variants) for later
1517 finish_struct_bits (tree t)
1519 /* Fix up variants (if any). */
1520 fixup_type_variants (t);
1522 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1523 /* For a class w/o baseclasses, 'finish_struct' has set
1524 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1525 Similarly for a class whose base classes do not have vtables.
1526 When neither of these is true, we might have removed abstract
1527 virtuals (by providing a definition), added some (by declaring
1528 new ones), or redeclared ones from a base class. We need to
1529 recalculate what's really an abstract virtual at this point (by
1530 looking in the vtables). */
1531 get_pure_virtuals (t);
1533 /* If this type has a copy constructor or a destructor, force its
1534 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1535 nonzero. This will cause it to be passed by invisible reference
1536 and prevent it from being returned in a register. */
1537 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1540 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1541 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1543 SET_TYPE_MODE (variants, BLKmode);
1544 TREE_ADDRESSABLE (variants) = 1;
1549 /* Issue warnings about T having private constructors, but no friends,
1552 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1553 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1554 non-private static member functions. */
1557 maybe_warn_about_overly_private_class (tree t)
1559 int has_member_fn = 0;
1560 int has_nonprivate_method = 0;
1563 if (!warn_ctor_dtor_privacy
1564 /* If the class has friends, those entities might create and
1565 access instances, so we should not warn. */
1566 || (CLASSTYPE_FRIEND_CLASSES (t)
1567 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1568 /* We will have warned when the template was declared; there's
1569 no need to warn on every instantiation. */
1570 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1571 /* There's no reason to even consider warning about this
1575 /* We only issue one warning, if more than one applies, because
1576 otherwise, on code like:
1579 // Oops - forgot `public:'
1585 we warn several times about essentially the same problem. */
1587 /* Check to see if all (non-constructor, non-destructor) member
1588 functions are private. (Since there are no friends or
1589 non-private statics, we can't ever call any of the private member
1591 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1592 /* We're not interested in compiler-generated methods; they don't
1593 provide any way to call private members. */
1594 if (!DECL_ARTIFICIAL (fn))
1596 if (!TREE_PRIVATE (fn))
1598 if (DECL_STATIC_FUNCTION_P (fn))
1599 /* A non-private static member function is just like a
1600 friend; it can create and invoke private member
1601 functions, and be accessed without a class
1605 has_nonprivate_method = 1;
1606 /* Keep searching for a static member function. */
1608 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1612 if (!has_nonprivate_method && has_member_fn)
1614 /* There are no non-private methods, and there's at least one
1615 private member function that isn't a constructor or
1616 destructor. (If all the private members are
1617 constructors/destructors we want to use the code below that
1618 issues error messages specifically referring to
1619 constructors/destructors.) */
1621 tree binfo = TYPE_BINFO (t);
1623 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1624 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1626 has_nonprivate_method = 1;
1629 if (!has_nonprivate_method)
1631 warning (OPT_Wctor_dtor_privacy,
1632 "all member functions in class %qT are private", t);
1637 /* Even if some of the member functions are non-private, the class
1638 won't be useful for much if all the constructors or destructors
1639 are private: such an object can never be created or destroyed. */
1640 fn = CLASSTYPE_DESTRUCTORS (t);
1641 if (fn && TREE_PRIVATE (fn))
1643 warning (OPT_Wctor_dtor_privacy,
1644 "%q#T only defines a private destructor and has no friends",
1649 /* Warn about classes that have private constructors and no friends. */
1650 if (TYPE_HAS_USER_CONSTRUCTOR (t)
1651 /* Implicitly generated constructors are always public. */
1652 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1653 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1655 int nonprivate_ctor = 0;
1657 /* If a non-template class does not define a copy
1658 constructor, one is defined for it, enabling it to avoid
1659 this warning. For a template class, this does not
1660 happen, and so we would normally get a warning on:
1662 template <class T> class C { private: C(); };
1664 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1665 complete non-template or fully instantiated classes have this
1667 if (!TYPE_HAS_INIT_REF (t))
1668 nonprivate_ctor = 1;
1670 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1672 tree ctor = OVL_CURRENT (fn);
1673 /* Ideally, we wouldn't count copy constructors (or, in
1674 fact, any constructor that takes an argument of the
1675 class type as a parameter) because such things cannot
1676 be used to construct an instance of the class unless
1677 you already have one. But, for now at least, we're
1679 if (! TREE_PRIVATE (ctor))
1681 nonprivate_ctor = 1;
1686 if (nonprivate_ctor == 0)
1688 warning (OPT_Wctor_dtor_privacy,
1689 "%q#T only defines private constructors and has no friends",
1697 gt_pointer_operator new_value;
1701 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1704 method_name_cmp (const void* m1_p, const void* m2_p)
1706 const tree *const m1 = (const tree *) m1_p;
1707 const tree *const m2 = (const tree *) m2_p;
1709 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1711 if (*m1 == NULL_TREE)
1713 if (*m2 == NULL_TREE)
1715 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1720 /* This routine compares two fields like method_name_cmp but using the
1721 pointer operator in resort_field_decl_data. */
1724 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1726 const tree *const m1 = (const tree *) m1_p;
1727 const tree *const m2 = (const tree *) m2_p;
1728 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1730 if (*m1 == NULL_TREE)
1732 if (*m2 == NULL_TREE)
1735 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1736 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1737 resort_data.new_value (&d1, resort_data.cookie);
1738 resort_data.new_value (&d2, resort_data.cookie);
1745 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1748 resort_type_method_vec (void* obj,
1749 void* orig_obj ATTRIBUTE_UNUSED ,
1750 gt_pointer_operator new_value,
1753 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1754 int len = VEC_length (tree, method_vec);
1758 /* The type conversion ops have to live at the front of the vec, so we
1760 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1761 VEC_iterate (tree, method_vec, slot, fn);
1763 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1768 resort_data.new_value = new_value;
1769 resort_data.cookie = cookie;
1770 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1771 resort_method_name_cmp);
1775 /* Warn about duplicate methods in fn_fields.
1777 Sort methods that are not special (i.e., constructors, destructors,
1778 and type conversion operators) so that we can find them faster in
1782 finish_struct_methods (tree t)
1785 VEC(tree,gc) *method_vec;
1788 method_vec = CLASSTYPE_METHOD_VEC (t);
1792 len = VEC_length (tree, method_vec);
1794 /* Clear DECL_IN_AGGR_P for all functions. */
1795 for (fn_fields = TYPE_METHODS (t); fn_fields;
1796 fn_fields = TREE_CHAIN (fn_fields))
1797 DECL_IN_AGGR_P (fn_fields) = 0;
1799 /* Issue warnings about private constructors and such. If there are
1800 no methods, then some public defaults are generated. */
1801 maybe_warn_about_overly_private_class (t);
1803 /* The type conversion ops have to live at the front of the vec, so we
1805 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1806 VEC_iterate (tree, method_vec, slot, fn_fields);
1808 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1811 qsort (VEC_address (tree, method_vec) + slot,
1812 len-slot, sizeof (tree), method_name_cmp);
1815 /* Make BINFO's vtable have N entries, including RTTI entries,
1816 vbase and vcall offsets, etc. Set its type and call the back end
1820 layout_vtable_decl (tree binfo, int n)
1825 atype = build_cplus_array_type (vtable_entry_type,
1826 build_index_type (size_int (n - 1)));
1827 layout_type (atype);
1829 /* We may have to grow the vtable. */
1830 vtable = get_vtbl_decl_for_binfo (binfo);
1831 if (!same_type_p (TREE_TYPE (vtable), atype))
1833 TREE_TYPE (vtable) = atype;
1834 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1835 layout_decl (vtable, 0);
1839 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1840 have the same signature. */
1843 same_signature_p (const_tree fndecl, const_tree base_fndecl)
1845 /* One destructor overrides another if they are the same kind of
1847 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1848 && special_function_p (base_fndecl) == special_function_p (fndecl))
1850 /* But a non-destructor never overrides a destructor, nor vice
1851 versa, nor do different kinds of destructors override
1852 one-another. For example, a complete object destructor does not
1853 override a deleting destructor. */
1854 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1857 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1858 || (DECL_CONV_FN_P (fndecl)
1859 && DECL_CONV_FN_P (base_fndecl)
1860 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1861 DECL_CONV_FN_TYPE (base_fndecl))))
1863 tree types, base_types;
1864 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1865 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1866 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1867 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1868 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1874 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1878 base_derived_from (tree derived, tree base)
1882 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1884 if (probe == derived)
1886 else if (BINFO_VIRTUAL_P (probe))
1887 /* If we meet a virtual base, we can't follow the inheritance
1888 any more. See if the complete type of DERIVED contains
1889 such a virtual base. */
1890 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1896 typedef struct find_final_overrider_data_s {
1897 /* The function for which we are trying to find a final overrider. */
1899 /* The base class in which the function was declared. */
1900 tree declaring_base;
1901 /* The candidate overriders. */
1903 /* Path to most derived. */
1904 VEC(tree,heap) *path;
1905 } find_final_overrider_data;
1907 /* Add the overrider along the current path to FFOD->CANDIDATES.
1908 Returns true if an overrider was found; false otherwise. */
1911 dfs_find_final_overrider_1 (tree binfo,
1912 find_final_overrider_data *ffod,
1917 /* If BINFO is not the most derived type, try a more derived class.
1918 A definition there will overrider a definition here. */
1922 if (dfs_find_final_overrider_1
1923 (VEC_index (tree, ffod->path, depth), ffod, depth))
1927 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1930 tree *candidate = &ffod->candidates;
1932 /* Remove any candidates overridden by this new function. */
1935 /* If *CANDIDATE overrides METHOD, then METHOD
1936 cannot override anything else on the list. */
1937 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1939 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1940 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1941 *candidate = TREE_CHAIN (*candidate);
1943 candidate = &TREE_CHAIN (*candidate);
1946 /* Add the new function. */
1947 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1954 /* Called from find_final_overrider via dfs_walk. */
1957 dfs_find_final_overrider_pre (tree binfo, void *data)
1959 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1961 if (binfo == ffod->declaring_base)
1962 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1963 VEC_safe_push (tree, heap, ffod->path, binfo);
1969 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1971 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1972 VEC_pop (tree, ffod->path);
1977 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1978 FN and whose TREE_VALUE is the binfo for the base where the
1979 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1980 DERIVED) is the base object in which FN is declared. */
1983 find_final_overrider (tree derived, tree binfo, tree fn)
1985 find_final_overrider_data ffod;
1987 /* Getting this right is a little tricky. This is valid:
1989 struct S { virtual void f (); };
1990 struct T { virtual void f (); };
1991 struct U : public S, public T { };
1993 even though calling `f' in `U' is ambiguous. But,
1995 struct R { virtual void f(); };
1996 struct S : virtual public R { virtual void f (); };
1997 struct T : virtual public R { virtual void f (); };
1998 struct U : public S, public T { };
2000 is not -- there's no way to decide whether to put `S::f' or
2001 `T::f' in the vtable for `R'.
2003 The solution is to look at all paths to BINFO. If we find
2004 different overriders along any two, then there is a problem. */
2005 if (DECL_THUNK_P (fn))
2006 fn = THUNK_TARGET (fn);
2008 /* Determine the depth of the hierarchy. */
2010 ffod.declaring_base = binfo;
2011 ffod.candidates = NULL_TREE;
2012 ffod.path = VEC_alloc (tree, heap, 30);
2014 dfs_walk_all (derived, dfs_find_final_overrider_pre,
2015 dfs_find_final_overrider_post, &ffod);
2017 VEC_free (tree, heap, ffod.path);
2019 /* If there was no winner, issue an error message. */
2020 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
2021 return error_mark_node;
2023 return ffod.candidates;
2026 /* Return the index of the vcall offset for FN when TYPE is used as a
2030 get_vcall_index (tree fn, tree type)
2032 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
2036 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
2037 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2038 || same_signature_p (fn, p->purpose))
2041 /* There should always be an appropriate index. */
2045 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2046 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2047 corresponding position in the BINFO_VIRTUALS list. */
2050 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2058 tree overrider_fn, overrider_target;
2059 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2060 tree over_return, base_return;
2063 /* Find the nearest primary base (possibly binfo itself) which defines
2064 this function; this is the class the caller will convert to when
2065 calling FN through BINFO. */
2066 for (b = binfo; ; b = get_primary_binfo (b))
2069 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2072 /* The nearest definition is from a lost primary. */
2073 if (BINFO_LOST_PRIMARY_P (b))
2078 /* Find the final overrider. */
2079 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2080 if (overrider == error_mark_node)
2082 error ("no unique final overrider for %qD in %qT", target_fn, t);
2085 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2087 /* Check for adjusting covariant return types. */
2088 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2089 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2091 if (POINTER_TYPE_P (over_return)
2092 && TREE_CODE (over_return) == TREE_CODE (base_return)
2093 && CLASS_TYPE_P (TREE_TYPE (over_return))
2094 && CLASS_TYPE_P (TREE_TYPE (base_return))
2095 /* If the overrider is invalid, don't even try. */
2096 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2098 /* If FN is a covariant thunk, we must figure out the adjustment
2099 to the final base FN was converting to. As OVERRIDER_TARGET might
2100 also be converting to the return type of FN, we have to
2101 combine the two conversions here. */
2102 tree fixed_offset, virtual_offset;
2104 over_return = TREE_TYPE (over_return);
2105 base_return = TREE_TYPE (base_return);
2107 if (DECL_THUNK_P (fn))
2109 gcc_assert (DECL_RESULT_THUNK_P (fn));
2110 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2111 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2114 fixed_offset = virtual_offset = NULL_TREE;
2117 /* Find the equivalent binfo within the return type of the
2118 overriding function. We will want the vbase offset from
2120 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2122 else if (!same_type_ignoring_top_level_qualifiers_p
2123 (over_return, base_return))
2125 /* There was no existing virtual thunk (which takes
2126 precedence). So find the binfo of the base function's
2127 return type within the overriding function's return type.
2128 We cannot call lookup base here, because we're inside a
2129 dfs_walk, and will therefore clobber the BINFO_MARKED
2130 flags. Fortunately we know the covariancy is valid (it
2131 has already been checked), so we can just iterate along
2132 the binfos, which have been chained in inheritance graph
2133 order. Of course it is lame that we have to repeat the
2134 search here anyway -- we should really be caching pieces
2135 of the vtable and avoiding this repeated work. */
2136 tree thunk_binfo, base_binfo;
2138 /* Find the base binfo within the overriding function's
2139 return type. We will always find a thunk_binfo, except
2140 when the covariancy is invalid (which we will have
2141 already diagnosed). */
2142 for (base_binfo = TYPE_BINFO (base_return),
2143 thunk_binfo = TYPE_BINFO (over_return);
2145 thunk_binfo = TREE_CHAIN (thunk_binfo))
2146 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2147 BINFO_TYPE (base_binfo)))
2150 /* See if virtual inheritance is involved. */
2151 for (virtual_offset = thunk_binfo;
2153 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2154 if (BINFO_VIRTUAL_P (virtual_offset))
2158 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2160 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2164 /* We convert via virtual base. Adjust the fixed
2165 offset to be from there. */
2167 size_diffop (offset,
2169 BINFO_OFFSET (virtual_offset)));
2172 /* There was an existing fixed offset, this must be
2173 from the base just converted to, and the base the
2174 FN was thunking to. */
2175 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2177 fixed_offset = offset;
2181 if (fixed_offset || virtual_offset)
2182 /* Replace the overriding function with a covariant thunk. We
2183 will emit the overriding function in its own slot as
2185 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2186 fixed_offset, virtual_offset);
2189 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) ||
2190 !DECL_THUNK_P (fn));
2192 /* Assume that we will produce a thunk that convert all the way to
2193 the final overrider, and not to an intermediate virtual base. */
2194 virtual_base = NULL_TREE;
2196 /* See if we can convert to an intermediate virtual base first, and then
2197 use the vcall offset located there to finish the conversion. */
2198 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2200 /* If we find the final overrider, then we can stop
2202 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2203 BINFO_TYPE (TREE_VALUE (overrider))))
2206 /* If we find a virtual base, and we haven't yet found the
2207 overrider, then there is a virtual base between the
2208 declaring base (first_defn) and the final overrider. */
2209 if (BINFO_VIRTUAL_P (b))
2216 if (overrider_fn != overrider_target && !virtual_base)
2218 /* The ABI specifies that a covariant thunk includes a mangling
2219 for a this pointer adjustment. This-adjusting thunks that
2220 override a function from a virtual base have a vcall
2221 adjustment. When the virtual base in question is a primary
2222 virtual base, we know the adjustments are zero, (and in the
2223 non-covariant case, we would not use the thunk).
2224 Unfortunately we didn't notice this could happen, when
2225 designing the ABI and so never mandated that such a covariant
2226 thunk should be emitted. Because we must use the ABI mandated
2227 name, we must continue searching from the binfo where we
2228 found the most recent definition of the function, towards the
2229 primary binfo which first introduced the function into the
2230 vtable. If that enters a virtual base, we must use a vcall
2231 this-adjusting thunk. Bleah! */
2232 tree probe = first_defn;
2234 while ((probe = get_primary_binfo (probe))
2235 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2236 if (BINFO_VIRTUAL_P (probe))
2237 virtual_base = probe;
2240 /* Even if we find a virtual base, the correct delta is
2241 between the overrider and the binfo we're building a vtable
2243 goto virtual_covariant;
2246 /* Compute the constant adjustment to the `this' pointer. The
2247 `this' pointer, when this function is called, will point at BINFO
2248 (or one of its primary bases, which are at the same offset). */
2250 /* The `this' pointer needs to be adjusted from the declaration to
2251 the nearest virtual base. */
2252 delta = size_diffop_loc (input_location,
2253 convert (ssizetype, BINFO_OFFSET (virtual_base)),
2254 convert (ssizetype, BINFO_OFFSET (first_defn)));
2256 /* If the nearest definition is in a lost primary, we don't need an
2257 entry in our vtable. Except possibly in a constructor vtable,
2258 if we happen to get our primary back. In that case, the offset
2259 will be zero, as it will be a primary base. */
2260 delta = size_zero_node;
2262 /* The `this' pointer needs to be adjusted from pointing to
2263 BINFO to pointing at the base where the final overrider
2266 delta = size_diffop_loc (input_location,
2268 BINFO_OFFSET (TREE_VALUE (overrider))),
2269 convert (ssizetype, BINFO_OFFSET (binfo)));
2271 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2274 BV_VCALL_INDEX (*virtuals)
2275 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2277 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2280 /* Called from modify_all_vtables via dfs_walk. */
2283 dfs_modify_vtables (tree binfo, void* data)
2285 tree t = (tree) data;
2290 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2291 /* A base without a vtable needs no modification, and its bases
2292 are uninteresting. */
2293 return dfs_skip_bases;
2295 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2296 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2297 /* Don't do the primary vtable, if it's new. */
2300 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2301 /* There's no need to modify the vtable for a non-virtual primary
2302 base; we're not going to use that vtable anyhow. We do still
2303 need to do this for virtual primary bases, as they could become
2304 non-primary in a construction vtable. */
2307 make_new_vtable (t, binfo);
2309 /* Now, go through each of the virtual functions in the virtual
2310 function table for BINFO. Find the final overrider, and update
2311 the BINFO_VIRTUALS list appropriately. */
2312 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2313 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2315 ix++, virtuals = TREE_CHAIN (virtuals),
2316 old_virtuals = TREE_CHAIN (old_virtuals))
2317 update_vtable_entry_for_fn (t,
2319 BV_FN (old_virtuals),
2325 /* Update all of the primary and secondary vtables for T. Create new
2326 vtables as required, and initialize their RTTI information. Each
2327 of the functions in VIRTUALS is declared in T and may override a
2328 virtual function from a base class; find and modify the appropriate
2329 entries to point to the overriding functions. Returns a list, in
2330 declaration order, of the virtual functions that are declared in T,
2331 but do not appear in the primary base class vtable, and which
2332 should therefore be appended to the end of the vtable for T. */
2335 modify_all_vtables (tree t, tree virtuals)
2337 tree binfo = TYPE_BINFO (t);
2340 /* Update all of the vtables. */
2341 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2343 /* Add virtual functions not already in our primary vtable. These
2344 will be both those introduced by this class, and those overridden
2345 from secondary bases. It does not include virtuals merely
2346 inherited from secondary bases. */
2347 for (fnsp = &virtuals; *fnsp; )
2349 tree fn = TREE_VALUE (*fnsp);
2351 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2352 || DECL_VINDEX (fn) == error_mark_node)
2354 /* We don't need to adjust the `this' pointer when
2355 calling this function. */
2356 BV_DELTA (*fnsp) = integer_zero_node;
2357 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2359 /* This is a function not already in our vtable. Keep it. */
2360 fnsp = &TREE_CHAIN (*fnsp);
2363 /* We've already got an entry for this function. Skip it. */
2364 *fnsp = TREE_CHAIN (*fnsp);
2370 /* Get the base virtual function declarations in T that have the
2374 get_basefndecls (tree name, tree t)
2377 tree base_fndecls = NULL_TREE;
2378 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2381 /* Find virtual functions in T with the indicated NAME. */
2382 i = lookup_fnfields_1 (t, name);
2384 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2386 methods = OVL_NEXT (methods))
2388 tree method = OVL_CURRENT (methods);
2390 if (TREE_CODE (method) == FUNCTION_DECL
2391 && DECL_VINDEX (method))
2392 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2396 return base_fndecls;
2398 for (i = 0; i < n_baseclasses; i++)
2400 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2401 base_fndecls = chainon (get_basefndecls (name, basetype),
2405 return base_fndecls;
2408 /* If this declaration supersedes the declaration of
2409 a method declared virtual in the base class, then
2410 mark this field as being virtual as well. */
2413 check_for_override (tree decl, tree ctype)
2415 if (TREE_CODE (decl) == TEMPLATE_DECL)
2416 /* In [temp.mem] we have:
2418 A specialization of a member function template does not
2419 override a virtual function from a base class. */
2421 if ((DECL_DESTRUCTOR_P (decl)
2422 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2423 || DECL_CONV_FN_P (decl))
2424 && look_for_overrides (ctype, decl)
2425 && !DECL_STATIC_FUNCTION_P (decl))
2426 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2427 the error_mark_node so that we know it is an overriding
2429 DECL_VINDEX (decl) = decl;
2431 if (DECL_VIRTUAL_P (decl))
2433 if (!DECL_VINDEX (decl))
2434 DECL_VINDEX (decl) = error_mark_node;
2435 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2439 /* Warn about hidden virtual functions that are not overridden in t.
2440 We know that constructors and destructors don't apply. */
2443 warn_hidden (tree t)
2445 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2449 /* We go through each separately named virtual function. */
2450 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2451 VEC_iterate (tree, method_vec, i, fns);
2462 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2463 have the same name. Figure out what name that is. */
2464 name = DECL_NAME (OVL_CURRENT (fns));
2465 /* There are no possibly hidden functions yet. */
2466 base_fndecls = NULL_TREE;
2467 /* Iterate through all of the base classes looking for possibly
2468 hidden functions. */
2469 for (binfo = TYPE_BINFO (t), j = 0;
2470 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2472 tree basetype = BINFO_TYPE (base_binfo);
2473 base_fndecls = chainon (get_basefndecls (name, basetype),
2477 /* If there are no functions to hide, continue. */
2481 /* Remove any overridden functions. */
2482 for (fn = fns; fn; fn = OVL_NEXT (fn))
2484 fndecl = OVL_CURRENT (fn);
2485 if (DECL_VINDEX (fndecl))
2487 tree *prev = &base_fndecls;
2490 /* If the method from the base class has the same
2491 signature as the method from the derived class, it
2492 has been overridden. */
2493 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2494 *prev = TREE_CHAIN (*prev);
2496 prev = &TREE_CHAIN (*prev);
2500 /* Now give a warning for all base functions without overriders,
2501 as they are hidden. */
2502 while (base_fndecls)
2504 /* Here we know it is a hider, and no overrider exists. */
2505 warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls));
2506 warning (OPT_Woverloaded_virtual, " by %q+D", fns);
2507 base_fndecls = TREE_CHAIN (base_fndecls);
2512 /* Check for things that are invalid. There are probably plenty of other
2513 things we should check for also. */
2516 finish_struct_anon (tree t)
2520 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2522 if (TREE_STATIC (field))
2524 if (TREE_CODE (field) != FIELD_DECL)
2527 if (DECL_NAME (field) == NULL_TREE
2528 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2530 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
2531 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2532 for (; elt; elt = TREE_CHAIN (elt))
2534 /* We're generally only interested in entities the user
2535 declared, but we also find nested classes by noticing
2536 the TYPE_DECL that we create implicitly. You're
2537 allowed to put one anonymous union inside another,
2538 though, so we explicitly tolerate that. We use
2539 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2540 we also allow unnamed types used for defining fields. */
2541 if (DECL_ARTIFICIAL (elt)
2542 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2543 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2546 if (TREE_CODE (elt) != FIELD_DECL)
2549 permerror (input_location, "%q+#D invalid; an anonymous union can "
2550 "only have non-static data members", elt);
2552 permerror (input_location, "%q+#D invalid; an anonymous struct can "
2553 "only have non-static data members", elt);
2557 if (TREE_PRIVATE (elt))
2560 permerror (input_location, "private member %q+#D in anonymous union", elt);
2562 permerror (input_location, "private member %q+#D in anonymous struct", elt);
2564 else if (TREE_PROTECTED (elt))
2567 permerror (input_location, "protected member %q+#D in anonymous union", elt);
2569 permerror (input_location, "protected member %q+#D in anonymous struct", elt);
2572 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2573 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2579 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2580 will be used later during class template instantiation.
2581 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2582 a non-static member data (FIELD_DECL), a member function
2583 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2584 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2585 When FRIEND_P is nonzero, T is either a friend class
2586 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2587 (FUNCTION_DECL, TEMPLATE_DECL). */
2590 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2592 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2593 if (CLASSTYPE_TEMPLATE_INFO (type))
2594 CLASSTYPE_DECL_LIST (type)
2595 = tree_cons (friend_p ? NULL_TREE : type,
2596 t, CLASSTYPE_DECL_LIST (type));
2599 /* Create default constructors, assignment operators, and so forth for
2600 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2601 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2602 the class cannot have a default constructor, copy constructor
2603 taking a const reference argument, or an assignment operator taking
2604 a const reference, respectively. */
2607 add_implicitly_declared_members (tree t,
2608 int cant_have_const_cctor,
2609 int cant_have_const_assignment)
2612 if (!CLASSTYPE_DESTRUCTORS (t))
2614 /* In general, we create destructors lazily. */
2615 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2616 /* However, if the implicit destructor is non-trivial
2617 destructor, we sometimes have to create it at this point. */
2618 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2622 if (TYPE_FOR_JAVA (t))
2623 /* If this a Java class, any non-trivial destructor is
2624 invalid, even if compiler-generated. Therefore, if the
2625 destructor is non-trivial we create it now. */
2633 /* If the implicit destructor will be virtual, then we must
2634 generate it now because (unfortunately) we do not
2635 generate virtual tables lazily. */
2636 binfo = TYPE_BINFO (t);
2637 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2642 base_type = BINFO_TYPE (base_binfo);
2643 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2644 if (dtor && DECL_VIRTUAL_P (dtor))
2652 /* If we can't get away with being lazy, generate the destructor
2655 lazily_declare_fn (sfk_destructor, t);
2661 If there is no user-declared constructor for a class, a default
2662 constructor is implicitly declared. */
2663 if (! TYPE_HAS_USER_CONSTRUCTOR (t))
2665 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2666 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2671 If a class definition does not explicitly declare a copy
2672 constructor, one is declared implicitly. */
2673 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2675 TYPE_HAS_INIT_REF (t) = 1;
2676 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2677 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2680 /* Currently only lambdas get a lazy move ctor. */
2681 if (LAMBDA_TYPE_P (t))
2682 CLASSTYPE_LAZY_MOVE_CTOR (t) = 1;
2684 /* If there is no assignment operator, one will be created if and
2685 when it is needed. For now, just record whether or not the type
2686 of the parameter to the assignment operator will be a const or
2687 non-const reference. */
2688 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2690 TYPE_HAS_ASSIGN_REF (t) = 1;
2691 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2692 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2696 /* Subroutine of finish_struct_1. Recursively count the number of fields
2697 in TYPE, including anonymous union members. */
2700 count_fields (tree fields)
2704 for (x = fields; x; x = TREE_CHAIN (x))
2706 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2707 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2714 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2715 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2718 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2721 for (x = fields; x; x = TREE_CHAIN (x))
2723 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2724 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2726 field_vec->elts[idx++] = x;
2731 /* FIELD is a bit-field. We are finishing the processing for its
2732 enclosing type. Issue any appropriate messages and set appropriate
2733 flags. Returns false if an error has been diagnosed. */
2736 check_bitfield_decl (tree field)
2738 tree type = TREE_TYPE (field);
2741 /* Extract the declared width of the bitfield, which has been
2742 temporarily stashed in DECL_INITIAL. */
2743 w = DECL_INITIAL (field);
2744 gcc_assert (w != NULL_TREE);
2745 /* Remove the bit-field width indicator so that the rest of the
2746 compiler does not treat that value as an initializer. */
2747 DECL_INITIAL (field) = NULL_TREE;
2749 /* Detect invalid bit-field type. */
2750 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type))
2752 error ("bit-field %q+#D with non-integral type", field);
2753 w = error_mark_node;
2757 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2760 /* detect invalid field size. */
2761 w = integral_constant_value (w);
2763 if (TREE_CODE (w) != INTEGER_CST)
2765 error ("bit-field %q+D width not an integer constant", field);
2766 w = error_mark_node;
2768 else if (tree_int_cst_sgn (w) < 0)
2770 error ("negative width in bit-field %q+D", field);
2771 w = error_mark_node;
2773 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2775 error ("zero width for bit-field %q+D", field);
2776 w = error_mark_node;
2778 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2779 && TREE_CODE (type) != ENUMERAL_TYPE
2780 && TREE_CODE (type) != BOOLEAN_TYPE)
2781 warning (0, "width of %q+D exceeds its type", field);
2782 else if (TREE_CODE (type) == ENUMERAL_TYPE
2783 && (0 > compare_tree_int (w,
2784 tree_int_cst_min_precision
2785 (TYPE_MIN_VALUE (type),
2786 TYPE_UNSIGNED (type)))
2787 || 0 > compare_tree_int (w,
2788 tree_int_cst_min_precision
2789 (TYPE_MAX_VALUE (type),
2790 TYPE_UNSIGNED (type)))))
2791 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2794 if (w != error_mark_node)
2796 DECL_SIZE (field) = convert (bitsizetype, w);
2797 DECL_BIT_FIELD (field) = 1;
2802 /* Non-bit-fields are aligned for their type. */
2803 DECL_BIT_FIELD (field) = 0;
2804 CLEAR_DECL_C_BIT_FIELD (field);
2809 /* FIELD is a non bit-field. We are finishing the processing for its
2810 enclosing type T. Issue any appropriate messages and set appropriate
2814 check_field_decl (tree field,
2816 int* cant_have_const_ctor,
2817 int* no_const_asn_ref,
2818 int* any_default_members)
2820 tree type = strip_array_types (TREE_TYPE (field));
2822 /* An anonymous union cannot contain any fields which would change
2823 the settings of CANT_HAVE_CONST_CTOR and friends. */
2824 if (ANON_UNION_TYPE_P (type))
2826 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2827 structs. So, we recurse through their fields here. */
2828 else if (ANON_AGGR_TYPE_P (type))
2832 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2833 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2834 check_field_decl (fields, t, cant_have_const_ctor,
2835 no_const_asn_ref, any_default_members);
2837 /* Check members with class type for constructors, destructors,
2839 else if (CLASS_TYPE_P (type))
2841 /* Never let anything with uninheritable virtuals
2842 make it through without complaint. */
2843 abstract_virtuals_error (field, type);
2845 if (TREE_CODE (t) == UNION_TYPE)
2847 if (TYPE_NEEDS_CONSTRUCTING (type))
2848 error ("member %q+#D with constructor not allowed in union",
2850 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2851 error ("member %q+#D with destructor not allowed in union", field);
2852 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2853 error ("member %q+#D with copy assignment operator not allowed in union",
2858 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2859 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2860 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2861 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2862 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2863 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (type);
2866 if (!TYPE_HAS_CONST_INIT_REF (type))
2867 *cant_have_const_ctor = 1;
2869 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2870 *no_const_asn_ref = 1;
2872 if (DECL_INITIAL (field) != NULL_TREE)
2874 /* `build_class_init_list' does not recognize
2876 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2877 error ("multiple fields in union %qT initialized", t);
2878 *any_default_members = 1;
2882 /* Check the data members (both static and non-static), class-scoped
2883 typedefs, etc., appearing in the declaration of T. Issue
2884 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2885 declaration order) of access declarations; each TREE_VALUE in this
2886 list is a USING_DECL.
2888 In addition, set the following flags:
2891 The class is empty, i.e., contains no non-static data members.
2893 CANT_HAVE_CONST_CTOR_P
2894 This class cannot have an implicitly generated copy constructor
2895 taking a const reference.
2897 CANT_HAVE_CONST_ASN_REF
2898 This class cannot have an implicitly generated assignment
2899 operator taking a const reference.
2901 All of these flags should be initialized before calling this
2904 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2905 fields can be added by adding to this chain. */
2908 check_field_decls (tree t, tree *access_decls,
2909 int *cant_have_const_ctor_p,
2910 int *no_const_asn_ref_p)
2915 int any_default_members;
2917 int field_access = -1;
2919 /* Assume there are no access declarations. */
2920 *access_decls = NULL_TREE;
2921 /* Assume this class has no pointer members. */
2922 has_pointers = false;
2923 /* Assume none of the members of this class have default
2925 any_default_members = 0;
2927 for (field = &TYPE_FIELDS (t); *field; field = next)
2930 tree type = TREE_TYPE (x);
2931 int this_field_access;
2933 next = &TREE_CHAIN (x);
2935 if (TREE_CODE (x) == USING_DECL)
2937 /* Prune the access declaration from the list of fields. */
2938 *field = TREE_CHAIN (x);
2940 /* Save the access declarations for our caller. */
2941 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2943 /* Since we've reset *FIELD there's no reason to skip to the
2949 if (TREE_CODE (x) == TYPE_DECL
2950 || TREE_CODE (x) == TEMPLATE_DECL)
2953 /* If we've gotten this far, it's a data member, possibly static,
2954 or an enumerator. */
2955 DECL_CONTEXT (x) = t;
2957 /* When this goes into scope, it will be a non-local reference. */
2958 DECL_NONLOCAL (x) = 1;
2960 if (TREE_CODE (t) == UNION_TYPE)
2964 If a union contains a static data member, or a member of
2965 reference type, the program is ill-formed. */
2966 if (TREE_CODE (x) == VAR_DECL)
2968 error ("%q+D may not be static because it is a member of a union", x);
2971 if (TREE_CODE (type) == REFERENCE_TYPE)
2973 error ("%q+D may not have reference type %qT because"
2974 " it is a member of a union",
2980 /* Perform error checking that did not get done in
2982 if (TREE_CODE (type) == FUNCTION_TYPE)
2984 error ("field %q+D invalidly declared function type", x);
2985 type = build_pointer_type (type);
2986 TREE_TYPE (x) = type;
2988 else if (TREE_CODE (type) == METHOD_TYPE)
2990 error ("field %q+D invalidly declared method type", x);
2991 type = build_pointer_type (type);
2992 TREE_TYPE (x) = type;
2995 if (type == error_mark_node)
2998 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
3001 /* Now it can only be a FIELD_DECL. */
3003 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
3004 CLASSTYPE_NON_AGGREGATE (t) = 1;
3006 /* A standard-layout class is a class that:
3008 has the same access control (Clause 11) for all non-static data members,
3010 this_field_access = TREE_PROTECTED (x) ? 1 : TREE_PRIVATE (x) ? 2 : 0;
3011 if (field_access == -1)
3012 field_access = this_field_access;
3013 else if (this_field_access != field_access)
3014 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3016 /* If this is of reference type, check if it needs an init. */
3017 if (TREE_CODE (type) == REFERENCE_TYPE)
3019 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1;
3020 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3021 if (DECL_INITIAL (x) == NULL_TREE)
3022 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3024 /* ARM $12.6.2: [A member initializer list] (or, for an
3025 aggregate, initialization by a brace-enclosed list) is the
3026 only way to initialize nonstatic const and reference
3028 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3031 type = strip_array_types (type);
3033 if (TYPE_PACKED (t))
3035 if (!layout_pod_type_p (type) && !TYPE_PACKED (type))
3039 "ignoring packed attribute because of unpacked non-POD field %q+#D",
3043 else if (DECL_C_BIT_FIELD (x)
3044 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
3045 DECL_PACKED (x) = 1;
3048 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
3049 /* We don't treat zero-width bitfields as making a class
3054 /* The class is non-empty. */
3055 CLASSTYPE_EMPTY_P (t) = 0;
3056 /* The class is not even nearly empty. */
3057 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3058 /* If one of the data members contains an empty class,
3060 if (CLASS_TYPE_P (type)
3061 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3062 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
3065 /* This is used by -Weffc++ (see below). Warn only for pointers
3066 to members which might hold dynamic memory. So do not warn
3067 for pointers to functions or pointers to members. */
3068 if (TYPE_PTR_P (type)
3069 && !TYPE_PTRFN_P (type)
3070 && !TYPE_PTR_TO_MEMBER_P (type))
3071 has_pointers = true;
3073 if (CLASS_TYPE_P (type))
3075 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3076 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3077 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3078 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3081 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3082 CLASSTYPE_HAS_MUTABLE (t) = 1;
3084 if (! layout_pod_type_p (type))
3085 /* DR 148 now allows pointers to members (which are POD themselves),
3086 to be allowed in POD structs. */
3087 CLASSTYPE_NON_LAYOUT_POD_P (t) = 1;
3089 if (!std_layout_type_p (type))
3090 CLASSTYPE_NON_STD_LAYOUT (t) = 1;
3092 if (! zero_init_p (type))
3093 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3095 /* If any field is const, the structure type is pseudo-const. */
3096 if (CP_TYPE_CONST_P (type))
3098 C_TYPE_FIELDS_READONLY (t) = 1;
3099 if (DECL_INITIAL (x) == NULL_TREE)
3100 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3102 /* ARM $12.6.2: [A member initializer list] (or, for an
3103 aggregate, initialization by a brace-enclosed list) is the
3104 only way to initialize nonstatic const and reference
3106 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3108 /* A field that is pseudo-const makes the structure likewise. */
3109 else if (CLASS_TYPE_P (type))
3111 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3112 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3113 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3114 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3117 /* Core issue 80: A nonstatic data member is required to have a
3118 different name from the class iff the class has a
3119 user-declared constructor. */
3120 if (constructor_name_p (DECL_NAME (x), t)
3121 && TYPE_HAS_USER_CONSTRUCTOR (t))
3122 permerror (input_location, "field %q+#D with same name as class", x);
3124 /* We set DECL_C_BIT_FIELD in grokbitfield.
3125 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3126 if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x))
3127 check_field_decl (x, t,
3128 cant_have_const_ctor_p,
3130 &any_default_members);
3133 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3134 it should also define a copy constructor and an assignment operator to
3135 implement the correct copy semantic (deep vs shallow, etc.). As it is
3136 not feasible to check whether the constructors do allocate dynamic memory
3137 and store it within members, we approximate the warning like this:
3139 -- Warn only if there are members which are pointers
3140 -- Warn only if there is a non-trivial constructor (otherwise,
3141 there cannot be memory allocated).
3142 -- Warn only if there is a non-trivial destructor. We assume that the
3143 user at least implemented the cleanup correctly, and a destructor
3144 is needed to free dynamic memory.
3146 This seems enough for practical purposes. */
3149 && TYPE_HAS_USER_CONSTRUCTOR (t)
3150 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3151 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3153 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3155 if (! TYPE_HAS_INIT_REF (t))
3157 warning (OPT_Weffc__,
3158 " but does not override %<%T(const %T&)%>", t, t);
3159 if (!TYPE_HAS_ASSIGN_REF (t))
3160 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3162 else if (! TYPE_HAS_ASSIGN_REF (t))
3163 warning (OPT_Weffc__,
3164 " but does not override %<operator=(const %T&)%>", t);
3167 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3169 TYPE_PACKED (t) = 0;
3171 /* Check anonymous struct/anonymous union fields. */
3172 finish_struct_anon (t);
3174 /* We've built up the list of access declarations in reverse order.
3176 *access_decls = nreverse (*access_decls);
3179 /* If TYPE is an empty class type, records its OFFSET in the table of
3183 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3187 if (!is_empty_class (type))
3190 /* Record the location of this empty object in OFFSETS. */
3191 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3193 n = splay_tree_insert (offsets,
3194 (splay_tree_key) offset,
3195 (splay_tree_value) NULL_TREE);
3196 n->value = ((splay_tree_value)
3197 tree_cons (NULL_TREE,
3204 /* Returns nonzero if TYPE is an empty class type and there is
3205 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3208 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3213 if (!is_empty_class (type))
3216 /* Record the location of this empty object in OFFSETS. */
3217 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3221 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3222 if (same_type_p (TREE_VALUE (t), type))
3228 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3229 F for every subobject, passing it the type, offset, and table of
3230 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3233 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3234 than MAX_OFFSET will not be walked.
3236 If F returns a nonzero value, the traversal ceases, and that value
3237 is returned. Otherwise, returns zero. */
3240 walk_subobject_offsets (tree type,
3241 subobject_offset_fn f,
3248 tree type_binfo = NULL_TREE;
3250 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3252 if (max_offset && INT_CST_LT (max_offset, offset))
3255 if (type == error_mark_node)
3260 if (abi_version_at_least (2))
3262 type = BINFO_TYPE (type);
3265 if (CLASS_TYPE_P (type))
3271 /* Avoid recursing into objects that are not interesting. */
3272 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3275 /* Record the location of TYPE. */
3276 r = (*f) (type, offset, offsets);
3280 /* Iterate through the direct base classes of TYPE. */
3282 type_binfo = TYPE_BINFO (type);
3283 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3287 if (abi_version_at_least (2)
3288 && BINFO_VIRTUAL_P (binfo))
3292 && BINFO_VIRTUAL_P (binfo)
3293 && !BINFO_PRIMARY_P (binfo))
3296 if (!abi_version_at_least (2))
3297 binfo_offset = size_binop (PLUS_EXPR,
3299 BINFO_OFFSET (binfo));
3303 /* We cannot rely on BINFO_OFFSET being set for the base
3304 class yet, but the offsets for direct non-virtual
3305 bases can be calculated by going back to the TYPE. */
3306 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3307 binfo_offset = size_binop (PLUS_EXPR,
3309 BINFO_OFFSET (orig_binfo));
3312 r = walk_subobject_offsets (binfo,
3317 (abi_version_at_least (2)
3318 ? /*vbases_p=*/0 : vbases_p));
3323 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3326 VEC(tree,gc) *vbases;
3328 /* Iterate through the virtual base classes of TYPE. In G++
3329 3.2, we included virtual bases in the direct base class
3330 loop above, which results in incorrect results; the
3331 correct offsets for virtual bases are only known when
3332 working with the most derived type. */
3334 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3335 VEC_iterate (tree, vbases, ix, binfo); ix++)
3337 r = walk_subobject_offsets (binfo,
3339 size_binop (PLUS_EXPR,
3341 BINFO_OFFSET (binfo)),
3350 /* We still have to walk the primary base, if it is
3351 virtual. (If it is non-virtual, then it was walked
3353 tree vbase = get_primary_binfo (type_binfo);
3355 if (vbase && BINFO_VIRTUAL_P (vbase)
3356 && BINFO_PRIMARY_P (vbase)
3357 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3359 r = (walk_subobject_offsets
3361 offsets, max_offset, /*vbases_p=*/0));
3368 /* Iterate through the fields of TYPE. */
3369 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3370 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3374 if (abi_version_at_least (2))
3375 field_offset = byte_position (field);
3377 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3378 field_offset = DECL_FIELD_OFFSET (field);
3380 r = walk_subobject_offsets (TREE_TYPE (field),
3382 size_binop (PLUS_EXPR,
3392 else if (TREE_CODE (type) == ARRAY_TYPE)
3394 tree element_type = strip_array_types (type);
3395 tree domain = TYPE_DOMAIN (type);
3398 /* Avoid recursing into objects that are not interesting. */
3399 if (!CLASS_TYPE_P (element_type)
3400 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3403 /* Step through each of the elements in the array. */
3404 for (index = size_zero_node;
3405 /* G++ 3.2 had an off-by-one error here. */
3406 (abi_version_at_least (2)
3407 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3408 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3409 index = size_binop (PLUS_EXPR, index, size_one_node))
3411 r = walk_subobject_offsets (TREE_TYPE (type),
3419 offset = size_binop (PLUS_EXPR, offset,
3420 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3421 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3422 there's no point in iterating through the remaining
3423 elements of the array. */
3424 if (max_offset && INT_CST_LT (max_offset, offset))
3432 /* Record all of the empty subobjects of TYPE (either a type or a
3433 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3434 is being placed at OFFSET; otherwise, it is a base class that is
3435 being placed at OFFSET. */
3438 record_subobject_offsets (tree type,
3441 bool is_data_member)
3444 /* If recording subobjects for a non-static data member or a
3445 non-empty base class , we do not need to record offsets beyond
3446 the size of the biggest empty class. Additional data members
3447 will go at the end of the class. Additional base classes will go
3448 either at offset zero (if empty, in which case they cannot
3449 overlap with offsets past the size of the biggest empty class) or
3450 at the end of the class.
3452 However, if we are placing an empty base class, then we must record
3453 all offsets, as either the empty class is at offset zero (where
3454 other empty classes might later be placed) or at the end of the
3455 class (where other objects might then be placed, so other empty
3456 subobjects might later overlap). */
3458 || !is_empty_class (BINFO_TYPE (type)))
3459 max_offset = sizeof_biggest_empty_class;
3461 max_offset = NULL_TREE;
3462 walk_subobject_offsets (type, record_subobject_offset, offset,
3463 offsets, max_offset, is_data_member);
3466 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3467 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3468 virtual bases of TYPE are examined. */
3471 layout_conflict_p (tree type,
3476 splay_tree_node max_node;
3478 /* Get the node in OFFSETS that indicates the maximum offset where
3479 an empty subobject is located. */
3480 max_node = splay_tree_max (offsets);
3481 /* If there aren't any empty subobjects, then there's no point in
3482 performing this check. */
3486 return walk_subobject_offsets (type, check_subobject_offset, offset,
3487 offsets, (tree) (max_node->key),
3491 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3492 non-static data member of the type indicated by RLI. BINFO is the
3493 binfo corresponding to the base subobject, OFFSETS maps offsets to
3494 types already located at those offsets. This function determines
3495 the position of the DECL. */
3498 layout_nonempty_base_or_field (record_layout_info rli,
3503 tree offset = NULL_TREE;
3509 /* For the purposes of determining layout conflicts, we want to
3510 use the class type of BINFO; TREE_TYPE (DECL) will be the
3511 CLASSTYPE_AS_BASE version, which does not contain entries for
3512 zero-sized bases. */
3513 type = TREE_TYPE (binfo);
3518 type = TREE_TYPE (decl);
3522 /* Try to place the field. It may take more than one try if we have
3523 a hard time placing the field without putting two objects of the
3524 same type at the same address. */
3527 struct record_layout_info_s old_rli = *rli;
3529 /* Place this field. */
3530 place_field (rli, decl);
3531 offset = byte_position (decl);
3533 /* We have to check to see whether or not there is already
3534 something of the same type at the offset we're about to use.
3535 For example, consider:
3538 struct T : public S { int i; };
3539 struct U : public S, public T {};
3541 Here, we put S at offset zero in U. Then, we can't put T at
3542 offset zero -- its S component would be at the same address
3543 as the S we already allocated. So, we have to skip ahead.
3544 Since all data members, including those whose type is an
3545 empty class, have nonzero size, any overlap can happen only
3546 with a direct or indirect base-class -- it can't happen with
3548 /* In a union, overlap is permitted; all members are placed at
3550 if (TREE_CODE (rli->t) == UNION_TYPE)
3552 /* G++ 3.2 did not check for overlaps when placing a non-empty
3554 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3556 if (layout_conflict_p (field_p ? type : binfo, offset,
3559 /* Strip off the size allocated to this field. That puts us
3560 at the first place we could have put the field with
3561 proper alignment. */
3564 /* Bump up by the alignment required for the type. */
3566 = size_binop (PLUS_EXPR, rli->bitpos,
3568 ? CLASSTYPE_ALIGN (type)
3569 : TYPE_ALIGN (type)));
3570 normalize_rli (rli);
3573 /* There was no conflict. We're done laying out this field. */
3577 /* Now that we know where it will be placed, update its
3579 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3580 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3581 this point because their BINFO_OFFSET is copied from another
3582 hierarchy. Therefore, we may not need to add the entire
3584 propagate_binfo_offsets (binfo,
3585 size_diffop_loc (input_location,
3586 convert (ssizetype, offset),
3588 BINFO_OFFSET (binfo))));
3591 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3594 empty_base_at_nonzero_offset_p (tree type,
3596 splay_tree offsets ATTRIBUTE_UNUSED)
3598 return is_empty_class (type) && !integer_zerop (offset);
3601 /* Layout the empty base BINFO. EOC indicates the byte currently just
3602 past the end of the class, and should be correctly aligned for a
3603 class of the type indicated by BINFO; OFFSETS gives the offsets of
3604 the empty bases allocated so far. T is the most derived
3605 type. Return nonzero iff we added it at the end. */
3608 layout_empty_base (record_layout_info rli, tree binfo,
3609 tree eoc, splay_tree offsets)
3612 tree basetype = BINFO_TYPE (binfo);
3615 /* This routine should only be used for empty classes. */
3616 gcc_assert (is_empty_class (basetype));
3617 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3619 if (!integer_zerop (BINFO_OFFSET (binfo)))
3621 if (abi_version_at_least (2))
3622 propagate_binfo_offsets
3623 (binfo, size_diffop_loc (input_location,
3624 size_zero_node, BINFO_OFFSET (binfo)));
3627 "offset of empty base %qT may not be ABI-compliant and may"
3628 "change in a future version of GCC",
3629 BINFO_TYPE (binfo));
3632 /* This is an empty base class. We first try to put it at offset
3634 if (layout_conflict_p (binfo,
3635 BINFO_OFFSET (binfo),
3639 /* That didn't work. Now, we move forward from the next
3640 available spot in the class. */
3642 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3645 if (!layout_conflict_p (binfo,
3646 BINFO_OFFSET (binfo),
3649 /* We finally found a spot where there's no overlap. */
3652 /* There's overlap here, too. Bump along to the next spot. */
3653 propagate_binfo_offsets (binfo, alignment);
3657 if (CLASSTYPE_USER_ALIGN (basetype))
3659 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype));
3661 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype));
3662 TYPE_USER_ALIGN (rli->t) = 1;
3668 /* Layout the base given by BINFO in the class indicated by RLI.
3669 *BASE_ALIGN is a running maximum of the alignments of
3670 any base class. OFFSETS gives the location of empty base
3671 subobjects. T is the most derived type. Return nonzero if the new
3672 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3673 *NEXT_FIELD, unless BINFO is for an empty base class.
3675 Returns the location at which the next field should be inserted. */
3678 build_base_field (record_layout_info rli, tree binfo,
3679 splay_tree offsets, tree *next_field)
3682 tree basetype = BINFO_TYPE (binfo);
3684 if (!COMPLETE_TYPE_P (basetype))
3685 /* This error is now reported in xref_tag, thus giving better
3686 location information. */
3689 /* Place the base class. */
3690 if (!is_empty_class (basetype))
3694 /* The containing class is non-empty because it has a non-empty
3696 CLASSTYPE_EMPTY_P (t) = 0;
3698 /* Create the FIELD_DECL. */
3699 decl = build_decl (input_location,
3700 FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3701 DECL_ARTIFICIAL (decl) = 1;
3702 DECL_IGNORED_P (decl) = 1;
3703 DECL_FIELD_CONTEXT (decl) = t;
3704 if (CLASSTYPE_AS_BASE (basetype))
3706 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3707 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3708 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3709 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3710 DECL_MODE (decl) = TYPE_MODE (basetype);
3711 DECL_FIELD_IS_BASE (decl) = 1;
3713 /* Try to place the field. It may take more than one try if we
3714 have a hard time placing the field without putting two
3715 objects of the same type at the same address. */
3716 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3717 /* Add the new FIELD_DECL to the list of fields for T. */
3718 TREE_CHAIN (decl) = *next_field;
3720 next_field = &TREE_CHAIN (decl);
3728 /* On some platforms (ARM), even empty classes will not be
3730 eoc = round_up_loc (input_location,
3731 rli_size_unit_so_far (rli),
3732 CLASSTYPE_ALIGN_UNIT (basetype));
3733 atend = layout_empty_base (rli, binfo, eoc, offsets);
3734 /* A nearly-empty class "has no proper base class that is empty,
3735 not morally virtual, and at an offset other than zero." */
3736 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3739 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3740 /* The check above (used in G++ 3.2) is insufficient because
3741 an empty class placed at offset zero might itself have an
3742 empty base at a nonzero offset. */
3743 else if (walk_subobject_offsets (basetype,
3744 empty_base_at_nonzero_offset_p,
3747 /*max_offset=*/NULL_TREE,
3750 if (abi_version_at_least (2))
3751 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3754 "class %qT will be considered nearly empty in a "
3755 "future version of GCC", t);
3759 /* We do not create a FIELD_DECL for empty base classes because
3760 it might overlap some other field. We want to be able to
3761 create CONSTRUCTORs for the class by iterating over the
3762 FIELD_DECLs, and the back end does not handle overlapping
3765 /* An empty virtual base causes a class to be non-empty
3766 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3767 here because that was already done when the virtual table
3768 pointer was created. */
3771 /* Record the offsets of BINFO and its base subobjects. */
3772 record_subobject_offsets (binfo,
3773 BINFO_OFFSET (binfo),
3775 /*is_data_member=*/false);
3780 /* Layout all of the non-virtual base classes. Record empty
3781 subobjects in OFFSETS. T is the most derived type. Return nonzero
3782 if the type cannot be nearly empty. The fields created
3783 corresponding to the base classes will be inserted at
3787 build_base_fields (record_layout_info rli,
3788 splay_tree offsets, tree *next_field)
3790 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3793 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3796 /* The primary base class is always allocated first. */
3797 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3798 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3799 offsets, next_field);
3801 /* Now allocate the rest of the bases. */
3802 for (i = 0; i < n_baseclasses; ++i)
3806 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3808 /* The primary base was already allocated above, so we don't
3809 need to allocate it again here. */
3810 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3813 /* Virtual bases are added at the end (a primary virtual base
3814 will have already been added). */
3815 if (BINFO_VIRTUAL_P (base_binfo))
3818 next_field = build_base_field (rli, base_binfo,
3819 offsets, next_field);
3823 /* Go through the TYPE_METHODS of T issuing any appropriate
3824 diagnostics, figuring out which methods override which other
3825 methods, and so forth. */
3828 check_methods (tree t)
3832 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3834 check_for_override (x, t);
3835 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3836 error ("initializer specified for non-virtual method %q+D", x);
3837 /* The name of the field is the original field name
3838 Save this in auxiliary field for later overloading. */
3839 if (DECL_VINDEX (x))
3841 TYPE_POLYMORPHIC_P (t) = 1;
3842 if (DECL_PURE_VIRTUAL_P (x))
3843 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3845 /* All user-provided destructors are non-trivial. */
3846 if (DECL_DESTRUCTOR_P (x) && user_provided_p (x))
3847 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3851 /* FN is a constructor or destructor. Clone the declaration to create
3852 a specialized in-charge or not-in-charge version, as indicated by
3856 build_clone (tree fn, tree name)
3861 /* Copy the function. */
3862 clone = copy_decl (fn);
3863 /* Reset the function name. */
3864 DECL_NAME (clone) = name;
3865 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3866 /* Remember where this function came from. */
3867 DECL_ABSTRACT_ORIGIN (clone) = fn;
3868 /* Make it easy to find the CLONE given the FN. */
3869 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3870 TREE_CHAIN (fn) = clone;
3872 /* If this is a template, do the rest on the DECL_TEMPLATE_RESULT. */
3873 if (TREE_CODE (clone) == TEMPLATE_DECL)
3875 tree result = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3876 DECL_TEMPLATE_RESULT (clone) = result;
3877 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3878 DECL_TI_TEMPLATE (result) = clone;
3879 TREE_TYPE (clone) = TREE_TYPE (result);
3883 DECL_CLONED_FUNCTION (clone) = fn;
3884 /* There's no pending inline data for this function. */
3885 DECL_PENDING_INLINE_INFO (clone) = NULL;
3886 DECL_PENDING_INLINE_P (clone) = 0;
3888 /* The base-class destructor is not virtual. */
3889 if (name == base_dtor_identifier)
3891 DECL_VIRTUAL_P (clone) = 0;
3892 if (TREE_CODE (clone) != TEMPLATE_DECL)
3893 DECL_VINDEX (clone) = NULL_TREE;
3896 /* If there was an in-charge parameter, drop it from the function
3898 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3904 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3905 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3906 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3907 /* Skip the `this' parameter. */
3908 parmtypes = TREE_CHAIN (parmtypes);
3909 /* Skip the in-charge parameter. */
3910 parmtypes = TREE_CHAIN (parmtypes);
3911 /* And the VTT parm, in a complete [cd]tor. */
3912 if (DECL_HAS_VTT_PARM_P (fn)
3913 && ! DECL_NEEDS_VTT_PARM_P (clone))
3914 parmtypes = TREE_CHAIN (parmtypes);
3915 /* If this is subobject constructor or destructor, add the vtt
3918 = build_method_type_directly (basetype,
3919 TREE_TYPE (TREE_TYPE (clone)),
3922 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3925 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3926 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3929 /* Copy the function parameters. */
3930 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3931 /* Remove the in-charge parameter. */
3932 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3934 TREE_CHAIN (DECL_ARGUMENTS (clone))
3935 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3936 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3938 /* And the VTT parm, in a complete [cd]tor. */
3939 if (DECL_HAS_VTT_PARM_P (fn))
3941 if (DECL_NEEDS_VTT_PARM_P (clone))
3942 DECL_HAS_VTT_PARM_P (clone) = 1;
3945 TREE_CHAIN (DECL_ARGUMENTS (clone))
3946 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3947 DECL_HAS_VTT_PARM_P (clone) = 0;
3951 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3953 DECL_CONTEXT (parms) = clone;
3954 cxx_dup_lang_specific_decl (parms);
3957 /* Create the RTL for this function. */
3958 SET_DECL_RTL (clone, NULL_RTX);
3959 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3962 note_decl_for_pch (clone);
3967 /* Implementation of DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P, do
3968 not invoke this function directly.
3970 For a non-thunk function, returns the address of the slot for storing
3971 the function it is a clone of. Otherwise returns NULL_TREE.
3973 If JUST_TESTING, looks through TEMPLATE_DECL and returns NULL if
3974 cloned_function is unset. This is to support the separate
3975 DECL_CLONED_FUNCTION and DECL_CLONED_FUNCTION_P modes; using the latter
3976 on a template makes sense, but not the former. */
3979 decl_cloned_function_p (const_tree decl, bool just_testing)
3983 decl = STRIP_TEMPLATE (decl);
3985 if (TREE_CODE (decl) != FUNCTION_DECL
3986 || !DECL_LANG_SPECIFIC (decl)
3987 || DECL_LANG_SPECIFIC (decl)->u.fn.thunk_p)
3989 #if defined ENABLE_TREE_CHECKING && (GCC_VERSION >= 2007)
3991 lang_check_failed (__FILE__, __LINE__, __FUNCTION__);
3997 ptr = &DECL_LANG_SPECIFIC (decl)->u.fn.u5.cloned_function;
3998 if (just_testing && *ptr == NULL_TREE)
4004 /* Produce declarations for all appropriate clones of FN. If
4005 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
4006 CLASTYPE_METHOD_VEC as well. */
4009 clone_function_decl (tree fn, int update_method_vec_p)
4013 /* Avoid inappropriate cloning. */
4015 && DECL_CLONED_FUNCTION_P (TREE_CHAIN (fn)))
4018 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
4020 /* For each constructor, we need two variants: an in-charge version
4021 and a not-in-charge version. */
4022 clone = build_clone (fn, complete_ctor_identifier);
4023 if (update_method_vec_p)
4024 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4025 clone = build_clone (fn, base_ctor_identifier);
4026 if (update_method_vec_p)
4027 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4031 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
4033 /* For each destructor, we need three variants: an in-charge
4034 version, a not-in-charge version, and an in-charge deleting
4035 version. We clone the deleting version first because that
4036 means it will go second on the TYPE_METHODS list -- and that
4037 corresponds to the correct layout order in the virtual
4040 For a non-virtual destructor, we do not build a deleting
4042 if (DECL_VIRTUAL_P (fn))
4044 clone = build_clone (fn, deleting_dtor_identifier);
4045 if (update_method_vec_p)
4046 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4048 clone = build_clone (fn, complete_dtor_identifier);
4049 if (update_method_vec_p)
4050 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4051 clone = build_clone (fn, base_dtor_identifier);
4052 if (update_method_vec_p)
4053 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
4056 /* Note that this is an abstract function that is never emitted. */
4057 DECL_ABSTRACT (fn) = 1;
4060 /* DECL is an in charge constructor, which is being defined. This will
4061 have had an in class declaration, from whence clones were
4062 declared. An out-of-class definition can specify additional default
4063 arguments. As it is the clones that are involved in overload
4064 resolution, we must propagate the information from the DECL to its
4068 adjust_clone_args (tree decl)
4072 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION_P (clone);
4073 clone = TREE_CHAIN (clone))
4075 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
4076 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
4077 tree decl_parms, clone_parms;
4079 clone_parms = orig_clone_parms;
4081 /* Skip the 'this' parameter. */
4082 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
4083 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4085 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
4086 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4087 if (DECL_HAS_VTT_PARM_P (decl))
4088 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
4090 clone_parms = orig_clone_parms;
4091 if (DECL_HAS_VTT_PARM_P (clone))
4092 clone_parms = TREE_CHAIN (clone_parms);
4094 for (decl_parms = orig_decl_parms; decl_parms;
4095 decl_parms = TREE_CHAIN (decl_parms),
4096 clone_parms = TREE_CHAIN (clone_parms))
4098 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
4099 TREE_TYPE (clone_parms)));
4101 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
4103 /* A default parameter has been added. Adjust the
4104 clone's parameters. */
4105 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4106 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4109 clone_parms = orig_decl_parms;
4111 if (DECL_HAS_VTT_PARM_P (clone))
4113 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
4114 TREE_VALUE (orig_clone_parms),
4116 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
4118 type = build_method_type_directly (basetype,
4119 TREE_TYPE (TREE_TYPE (clone)),
4122 type = build_exception_variant (type, exceptions);
4123 TREE_TYPE (clone) = type;
4125 clone_parms = NULL_TREE;
4129 gcc_assert (!clone_parms);
4133 /* For each of the constructors and destructors in T, create an
4134 in-charge and not-in-charge variant. */
4137 clone_constructors_and_destructors (tree t)
4141 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4143 if (!CLASSTYPE_METHOD_VEC (t))
4146 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4147 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4148 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4149 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4152 /* Returns true iff class T has a user-defined constructor other than
4153 the default constructor. */
4156 type_has_user_nondefault_constructor (tree t)
4160 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4163 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4165 tree fn = OVL_CURRENT (fns);
4166 if (!DECL_ARTIFICIAL (fn)
4167 && (TREE_CODE (fn) == TEMPLATE_DECL
4168 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
4176 /* Returns true iff FN is a user-provided function, i.e. user-declared
4177 and not defaulted at its first declaration; or explicit, private,
4178 protected, or non-const. */
4181 user_provided_p (tree fn)
4183 if (TREE_CODE (fn) == TEMPLATE_DECL)
4186 return (!DECL_ARTIFICIAL (fn)
4187 && !DECL_DEFAULTED_IN_CLASS_P (fn));
4190 /* Returns true iff class T has a user-provided constructor. */
4193 type_has_user_provided_constructor (tree t)
4197 if (!CLASS_TYPE_P (t))
4200 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4203 /* This can happen in error cases; avoid crashing. */
4204 if (!CLASSTYPE_METHOD_VEC (t))
4207 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4208 if (user_provided_p (OVL_CURRENT (fns)))
4214 /* Returns true iff class T has a user-provided default constructor. */
4217 type_has_user_provided_default_constructor (tree t)
4221 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4224 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4226 tree fn = OVL_CURRENT (fns);
4227 if (TREE_CODE (fn) == FUNCTION_DECL
4228 && user_provided_p (fn))
4230 args = FUNCTION_FIRST_USER_PARMTYPE (fn);
4231 while (args && TREE_PURPOSE (args))
4232 args = TREE_CHAIN (args);
4233 if (!args || args == void_list_node)
4241 /* Remove all zero-width bit-fields from T. */
4244 remove_zero_width_bit_fields (tree t)
4248 fieldsp = &TYPE_FIELDS (t);
4251 if (TREE_CODE (*fieldsp) == FIELD_DECL
4252 && DECL_C_BIT_FIELD (*fieldsp)
4253 && DECL_INITIAL (*fieldsp))
4254 *fieldsp = TREE_CHAIN (*fieldsp);
4256 fieldsp = &TREE_CHAIN (*fieldsp);
4260 /* Returns TRUE iff we need a cookie when dynamically allocating an
4261 array whose elements have the indicated class TYPE. */
4264 type_requires_array_cookie (tree type)
4267 bool has_two_argument_delete_p = false;
4269 gcc_assert (CLASS_TYPE_P (type));
4271 /* If there's a non-trivial destructor, we need a cookie. In order
4272 to iterate through the array calling the destructor for each
4273 element, we'll have to know how many elements there are. */
4274 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4277 /* If the usual deallocation function is a two-argument whose second
4278 argument is of type `size_t', then we have to pass the size of
4279 the array to the deallocation function, so we will need to store
4281 fns = lookup_fnfields (TYPE_BINFO (type),
4282 ansi_opname (VEC_DELETE_EXPR),
4284 /* If there are no `operator []' members, or the lookup is
4285 ambiguous, then we don't need a cookie. */
4286 if (!fns || fns == error_mark_node)
4288 /* Loop through all of the functions. */
4289 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4294 /* Select the current function. */
4295 fn = OVL_CURRENT (fns);
4296 /* See if this function is a one-argument delete function. If
4297 it is, then it will be the usual deallocation function. */
4298 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4299 if (second_parm == void_list_node)
4301 /* Do not consider this function if its second argument is an
4305 /* Otherwise, if we have a two-argument function and the second
4306 argument is `size_t', it will be the usual deallocation
4307 function -- unless there is one-argument function, too. */
4308 if (TREE_CHAIN (second_parm) == void_list_node
4309 && same_type_p (TREE_VALUE (second_parm), size_type_node))
4310 has_two_argument_delete_p = true;
4313 return has_two_argument_delete_p;
4316 /* Check the validity of the bases and members declared in T. Add any
4317 implicitly-generated functions (like copy-constructors and
4318 assignment operators). Compute various flag bits (like
4319 CLASSTYPE_NON_LAYOUT_POD_T) for T. This routine works purely at the C++
4320 level: i.e., independently of the ABI in use. */
4323 check_bases_and_members (tree t)
4325 /* Nonzero if the implicitly generated copy constructor should take
4326 a non-const reference argument. */
4327 int cant_have_const_ctor;
4328 /* Nonzero if the implicitly generated assignment operator
4329 should take a non-const reference argument. */
4330 int no_const_asn_ref;
4332 bool saved_complex_asn_ref;
4333 bool saved_nontrivial_dtor;
4336 /* By default, we use const reference arguments and generate default
4338 cant_have_const_ctor = 0;
4339 no_const_asn_ref = 0;
4341 /* Check all the base-classes. */
4342 check_bases (t, &cant_have_const_ctor,
4345 /* Check all the method declarations. */
4348 /* Save the initial values of these flags which only indicate whether
4349 or not the class has user-provided functions. As we analyze the
4350 bases and members we can set these flags for other reasons. */
4351 saved_complex_asn_ref = TYPE_HAS_COMPLEX_ASSIGN_REF (t);
4352 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
4354 /* Check all the data member declarations. We cannot call
4355 check_field_decls until we have called check_bases check_methods,
4356 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4357 being set appropriately. */
4358 check_field_decls (t, &access_decls,
4359 &cant_have_const_ctor,
4362 /* A nearly-empty class has to be vptr-containing; a nearly empty
4363 class contains just a vptr. */
4364 if (!TYPE_CONTAINS_VPTR_P (t))
4365 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4367 /* Do some bookkeeping that will guide the generation of implicitly
4368 declared member functions. */
4369 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4370 /* We need to call a constructor for this class if it has a
4371 user-provided constructor, or if the default constructor is going
4372 to initialize the vptr. (This is not an if-and-only-if;
4373 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4374 themselves need constructing.) */
4375 TYPE_NEEDS_CONSTRUCTING (t)
4376 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t));
4379 An aggregate is an array or a class with no user-provided
4380 constructors ... and no virtual functions.
4382 Again, other conditions for being an aggregate are checked
4384 CLASSTYPE_NON_AGGREGATE (t)
4385 |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t));
4386 /* This is the C++98/03 definition of POD; it changed in C++0x, but we
4387 retain the old definition internally for ABI reasons. */
4388 CLASSTYPE_NON_LAYOUT_POD_P (t)
4389 |= (CLASSTYPE_NON_AGGREGATE (t)
4390 || saved_nontrivial_dtor || saved_complex_asn_ref);
4391 CLASSTYPE_NON_STD_LAYOUT (t) |= TYPE_CONTAINS_VPTR_P (t);
4392 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4393 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
4395 /* If the class has no user-declared constructor, but does have
4396 non-static const or reference data members that can never be
4397 initialized, issue a warning. */
4398 if (warn_uninitialized
4399 /* Classes with user-declared constructors are presumed to
4400 initialize these members. */
4401 && !TYPE_HAS_USER_CONSTRUCTOR (t)
4402 /* Aggregates can be initialized with brace-enclosed
4404 && CLASSTYPE_NON_AGGREGATE (t))
4408 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4412 if (TREE_CODE (field) != FIELD_DECL)
4415 type = TREE_TYPE (field);
4416 if (TREE_CODE (type) == REFERENCE_TYPE)
4417 warning (OPT_Wuninitialized, "non-static reference %q+#D "
4418 "in class without a constructor", field);
4419 else if (CP_TYPE_CONST_P (type)
4420 && (!CLASS_TYPE_P (type)
4421 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type)))
4422 warning (OPT_Wuninitialized, "non-static const member %q+#D "
4423 "in class without a constructor", field);
4427 /* Synthesize any needed methods. */
4428 add_implicitly_declared_members (t,
4429 cant_have_const_ctor,
4432 /* Check defaulted declarations here so we have cant_have_const_ctor
4433 and don't need to worry about clones. */
4434 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4435 if (DECL_DEFAULTED_IN_CLASS_P (fn))
4437 int copy = copy_fn_p (fn);
4441 = (DECL_CONSTRUCTOR_P (fn) ? !cant_have_const_ctor
4442 : !no_const_asn_ref);
4443 bool fn_const_p = (copy == 2);
4445 if (fn_const_p && !imp_const_p)
4446 /* If the function is defaulted outside the class, we just
4447 give the synthesis error. */
4448 error ("%q+D declared to take const reference, but implicit "
4449 "declaration would take non-const", fn);
4450 else if (imp_const_p && !fn_const_p)
4451 error ("%q+D declared to take non-const reference cannot be "
4452 "defaulted in the class body", fn);
4454 defaulted_late_check (fn);
4457 if (LAMBDA_TYPE_P (t))
4459 /* "The closure type associated with a lambda-expression has a deleted
4460 default constructor and a deleted copy assignment operator." */
4461 TYPE_NEEDS_CONSTRUCTING (t) = 1;
4462 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 0;
4463 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 0;
4464 TYPE_HAS_ASSIGN_REF (t) = 0;
4465 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 0;
4467 /* "This class type is not an aggregate." */
4468 CLASSTYPE_NON_AGGREGATE (t) = 1;
4471 /* Create the in-charge and not-in-charge variants of constructors
4473 clone_constructors_and_destructors (t);
4475 /* Process the using-declarations. */
4476 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4477 handle_using_decl (TREE_VALUE (access_decls), t);
4479 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4480 finish_struct_methods (t);
4482 /* Figure out whether or not we will need a cookie when dynamically
4483 allocating an array of this type. */
4484 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4485 = type_requires_array_cookie (t);
4488 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4489 accordingly. If a new vfield was created (because T doesn't have a
4490 primary base class), then the newly created field is returned. It
4491 is not added to the TYPE_FIELDS list; it is the caller's
4492 responsibility to do that. Accumulate declared virtual functions
4496 create_vtable_ptr (tree t, tree* virtuals_p)
4500 /* Collect the virtual functions declared in T. */
4501 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4502 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4503 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4505 tree new_virtual = make_node (TREE_LIST);
4507 BV_FN (new_virtual) = fn;
4508 BV_DELTA (new_virtual) = integer_zero_node;
4509 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4511 TREE_CHAIN (new_virtual) = *virtuals_p;
4512 *virtuals_p = new_virtual;
4515 /* If we couldn't find an appropriate base class, create a new field
4516 here. Even if there weren't any new virtual functions, we might need a
4517 new virtual function table if we're supposed to include vptrs in
4518 all classes that need them. */
4519 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4521 /* We build this decl with vtbl_ptr_type_node, which is a
4522 `vtable_entry_type*'. It might seem more precise to use
4523 `vtable_entry_type (*)[N]' where N is the number of virtual
4524 functions. However, that would require the vtable pointer in
4525 base classes to have a different type than the vtable pointer
4526 in derived classes. We could make that happen, but that
4527 still wouldn't solve all the problems. In particular, the
4528 type-based alias analysis code would decide that assignments
4529 to the base class vtable pointer can't alias assignments to
4530 the derived class vtable pointer, since they have different
4531 types. Thus, in a derived class destructor, where the base
4532 class constructor was inlined, we could generate bad code for
4533 setting up the vtable pointer.
4535 Therefore, we use one type for all vtable pointers. We still
4536 use a type-correct type; it's just doesn't indicate the array
4537 bounds. That's better than using `void*' or some such; it's
4538 cleaner, and it let's the alias analysis code know that these
4539 stores cannot alias stores to void*! */
4542 field = build_decl (input_location,
4543 FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4544 DECL_VIRTUAL_P (field) = 1;
4545 DECL_ARTIFICIAL (field) = 1;
4546 DECL_FIELD_CONTEXT (field) = t;
4547 DECL_FCONTEXT (field) = t;
4549 TYPE_VFIELD (t) = field;
4551 /* This class is non-empty. */
4552 CLASSTYPE_EMPTY_P (t) = 0;
4560 /* Add OFFSET to all base types of BINFO which is a base in the
4561 hierarchy dominated by T.
4563 OFFSET, which is a type offset, is number of bytes. */
4566 propagate_binfo_offsets (tree binfo, tree offset)
4572 /* Update BINFO's offset. */
4573 BINFO_OFFSET (binfo)
4574 = convert (sizetype,
4575 size_binop (PLUS_EXPR,
4576 convert (ssizetype, BINFO_OFFSET (binfo)),
4579 /* Find the primary base class. */
4580 primary_binfo = get_primary_binfo (binfo);
4582 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4583 propagate_binfo_offsets (primary_binfo, offset);
4585 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4587 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4589 /* Don't do the primary base twice. */
4590 if (base_binfo == primary_binfo)
4593 if (BINFO_VIRTUAL_P (base_binfo))
4596 propagate_binfo_offsets (base_binfo, offset);
4600 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4601 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4602 empty subobjects of T. */
4605 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4609 bool first_vbase = true;
4612 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4615 if (!abi_version_at_least(2))
4617 /* In G++ 3.2, we incorrectly rounded the size before laying out
4618 the virtual bases. */
4619 finish_record_layout (rli, /*free_p=*/false);
4620 #ifdef STRUCTURE_SIZE_BOUNDARY
4621 /* Packed structures don't need to have minimum size. */
4622 if (! TYPE_PACKED (t))
4623 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4625 rli->offset = TYPE_SIZE_UNIT (t);
4626 rli->bitpos = bitsize_zero_node;
4627 rli->record_align = TYPE_ALIGN (t);
4630 /* Find the last field. The artificial fields created for virtual
4631 bases will go after the last extant field to date. */
4632 next_field = &TYPE_FIELDS (t);
4634 next_field = &TREE_CHAIN (*next_field);
4636 /* Go through the virtual bases, allocating space for each virtual
4637 base that is not already a primary base class. These are
4638 allocated in inheritance graph order. */
4639 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4641 if (!BINFO_VIRTUAL_P (vbase))
4644 if (!BINFO_PRIMARY_P (vbase))
4646 tree basetype = TREE_TYPE (vbase);
4648 /* This virtual base is not a primary base of any class in the
4649 hierarchy, so we have to add space for it. */
4650 next_field = build_base_field (rli, vbase,
4651 offsets, next_field);
4653 /* If the first virtual base might have been placed at a
4654 lower address, had we started from CLASSTYPE_SIZE, rather
4655 than TYPE_SIZE, issue a warning. There can be both false
4656 positives and false negatives from this warning in rare
4657 cases; to deal with all the possibilities would probably
4658 require performing both layout algorithms and comparing
4659 the results which is not particularly tractable. */
4663 (size_binop (CEIL_DIV_EXPR,
4664 round_up_loc (input_location,
4666 CLASSTYPE_ALIGN (basetype)),
4668 BINFO_OFFSET (vbase))))
4670 "offset of virtual base %qT is not ABI-compliant and "
4671 "may change in a future version of GCC",
4674 first_vbase = false;
4679 /* Returns the offset of the byte just past the end of the base class
4683 end_of_base (tree binfo)
4687 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo)))
4688 size = TYPE_SIZE_UNIT (char_type_node);
4689 else if (is_empty_class (BINFO_TYPE (binfo)))
4690 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4691 allocate some space for it. It cannot have virtual bases, so
4692 TYPE_SIZE_UNIT is fine. */
4693 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4695 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4697 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4700 /* Returns the offset of the byte just past the end of the base class
4701 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4702 only non-virtual bases are included. */
4705 end_of_class (tree t, int include_virtuals_p)
4707 tree result = size_zero_node;
4708 VEC(tree,gc) *vbases;
4714 for (binfo = TYPE_BINFO (t), i = 0;
4715 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4717 if (!include_virtuals_p
4718 && BINFO_VIRTUAL_P (base_binfo)
4719 && (!BINFO_PRIMARY_P (base_binfo)
4720 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4723 offset = end_of_base (base_binfo);
4724 if (INT_CST_LT_UNSIGNED (result, offset))
4728 /* G++ 3.2 did not check indirect virtual bases. */
4729 if (abi_version_at_least (2) && include_virtuals_p)
4730 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4731 VEC_iterate (tree, vbases, i, base_binfo); i++)
4733 offset = end_of_base (base_binfo);
4734 if (INT_CST_LT_UNSIGNED (result, offset))
4741 /* Warn about bases of T that are inaccessible because they are
4742 ambiguous. For example:
4745 struct T : public S {};
4746 struct U : public S, public T {};
4748 Here, `(S*) new U' is not allowed because there are two `S'
4752 warn_about_ambiguous_bases (tree t)
4755 VEC(tree,gc) *vbases;
4760 /* If there are no repeated bases, nothing can be ambiguous. */
4761 if (!CLASSTYPE_REPEATED_BASE_P (t))
4764 /* Check direct bases. */
4765 for (binfo = TYPE_BINFO (t), i = 0;
4766 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4768 basetype = BINFO_TYPE (base_binfo);
4770 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4771 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4775 /* Check for ambiguous virtual bases. */
4777 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4778 VEC_iterate (tree, vbases, i, binfo); i++)
4780 basetype = BINFO_TYPE (binfo);
4782 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4783 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity",
4788 /* Compare two INTEGER_CSTs K1 and K2. */
4791 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4793 return tree_int_cst_compare ((tree) k1, (tree) k2);
4796 /* Increase the size indicated in RLI to account for empty classes
4797 that are "off the end" of the class. */
4800 include_empty_classes (record_layout_info rli)
4805 /* It might be the case that we grew the class to allocate a
4806 zero-sized base class. That won't be reflected in RLI, yet,
4807 because we are willing to overlay multiple bases at the same
4808 offset. However, now we need to make sure that RLI is big enough
4809 to reflect the entire class. */
4810 eoc = end_of_class (rli->t,
4811 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4812 rli_size = rli_size_unit_so_far (rli);
4813 if (TREE_CODE (rli_size) == INTEGER_CST
4814 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4816 if (!abi_version_at_least (2))
4817 /* In version 1 of the ABI, the size of a class that ends with
4818 a bitfield was not rounded up to a whole multiple of a
4819 byte. Because rli_size_unit_so_far returns only the number
4820 of fully allocated bytes, any extra bits were not included
4822 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4824 /* The size should have been rounded to a whole byte. */
4825 gcc_assert (tree_int_cst_equal
4826 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4828 = size_binop (PLUS_EXPR,
4830 size_binop (MULT_EXPR,
4831 convert (bitsizetype,
4832 size_binop (MINUS_EXPR,
4834 bitsize_int (BITS_PER_UNIT)));
4835 normalize_rli (rli);
4839 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4840 BINFO_OFFSETs for all of the base-classes. Position the vtable
4841 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4844 layout_class_type (tree t, tree *virtuals_p)
4846 tree non_static_data_members;
4849 record_layout_info rli;
4850 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4851 types that appear at that offset. */
4852 splay_tree empty_base_offsets;
4853 /* True if the last field layed out was a bit-field. */
4854 bool last_field_was_bitfield = false;
4855 /* The location at which the next field should be inserted. */
4857 /* T, as a base class. */
4860 /* Keep track of the first non-static data member. */
4861 non_static_data_members = TYPE_FIELDS (t);
4863 /* Start laying out the record. */
4864 rli = start_record_layout (t);
4866 /* Mark all the primary bases in the hierarchy. */
4867 determine_primary_bases (t);
4869 /* Create a pointer to our virtual function table. */
4870 vptr = create_vtable_ptr (t, virtuals_p);
4872 /* The vptr is always the first thing in the class. */
4875 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4876 TYPE_FIELDS (t) = vptr;
4877 next_field = &TREE_CHAIN (vptr);
4878 place_field (rli, vptr);
4881 next_field = &TYPE_FIELDS (t);
4883 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4884 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4886 build_base_fields (rli, empty_base_offsets, next_field);
4888 /* Layout the non-static data members. */
4889 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4894 /* We still pass things that aren't non-static data members to
4895 the back end, in case it wants to do something with them. */
4896 if (TREE_CODE (field) != FIELD_DECL)
4898 place_field (rli, field);
4899 /* If the static data member has incomplete type, keep track
4900 of it so that it can be completed later. (The handling
4901 of pending statics in finish_record_layout is
4902 insufficient; consider:
4905 struct S2 { static S1 s1; };
4907 At this point, finish_record_layout will be called, but
4908 S1 is still incomplete.) */
4909 if (TREE_CODE (field) == VAR_DECL)
4911 maybe_register_incomplete_var (field);
4912 /* The visibility of static data members is determined
4913 at their point of declaration, not their point of
4915 determine_visibility (field);
4920 type = TREE_TYPE (field);
4921 if (type == error_mark_node)
4924 padding = NULL_TREE;
4926 /* If this field is a bit-field whose width is greater than its
4927 type, then there are some special rules for allocating
4929 if (DECL_C_BIT_FIELD (field)
4930 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4934 bool was_unnamed_p = false;
4935 /* We must allocate the bits as if suitably aligned for the
4936 longest integer type that fits in this many bits. type
4937 of the field. Then, we are supposed to use the left over
4938 bits as additional padding. */
4939 for (itk = itk_char; itk != itk_none; ++itk)
4940 if (INT_CST_LT (DECL_SIZE (field),
4941 TYPE_SIZE (integer_types[itk])))
4944 /* ITK now indicates a type that is too large for the
4945 field. We have to back up by one to find the largest
4947 integer_type = integer_types[itk - 1];
4949 /* Figure out how much additional padding is required. GCC
4950 3.2 always created a padding field, even if it had zero
4952 if (!abi_version_at_least (2)
4953 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4955 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4956 /* In a union, the padding field must have the full width
4957 of the bit-field; all fields start at offset zero. */
4958 padding = DECL_SIZE (field);
4961 if (TREE_CODE (t) == UNION_TYPE)
4962 warning (OPT_Wabi, "size assigned to %qT may not be "
4963 "ABI-compliant and may change in a future "
4966 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4967 TYPE_SIZE (integer_type));
4970 #ifdef PCC_BITFIELD_TYPE_MATTERS
4971 /* An unnamed bitfield does not normally affect the
4972 alignment of the containing class on a target where
4973 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4974 make any exceptions for unnamed bitfields when the
4975 bitfields are longer than their types. Therefore, we
4976 temporarily give the field a name. */
4977 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4979 was_unnamed_p = true;
4980 DECL_NAME (field) = make_anon_name ();
4983 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4984 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4985 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4986 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4987 empty_base_offsets);
4989 DECL_NAME (field) = NULL_TREE;
4990 /* Now that layout has been performed, set the size of the
4991 field to the size of its declared type; the rest of the
4992 field is effectively invisible. */
4993 DECL_SIZE (field) = TYPE_SIZE (type);
4994 /* We must also reset the DECL_MODE of the field. */
4995 if (abi_version_at_least (2))
4996 DECL_MODE (field) = TYPE_MODE (type);
4998 && DECL_MODE (field) != TYPE_MODE (type))
4999 /* Versions of G++ before G++ 3.4 did not reset the
5002 "the offset of %qD may not be ABI-compliant and may "
5003 "change in a future version of GCC", field);
5006 layout_nonempty_base_or_field (rli, field, NULL_TREE,
5007 empty_base_offsets);
5009 /* Remember the location of any empty classes in FIELD. */
5010 if (abi_version_at_least (2))
5011 record_subobject_offsets (TREE_TYPE (field),
5012 byte_position(field),
5014 /*is_data_member=*/true);
5016 /* If a bit-field does not immediately follow another bit-field,
5017 and yet it starts in the middle of a byte, we have failed to
5018 comply with the ABI. */
5020 && DECL_C_BIT_FIELD (field)
5021 /* The TREE_NO_WARNING flag gets set by Objective-C when
5022 laying out an Objective-C class. The ObjC ABI differs
5023 from the C++ ABI, and so we do not want a warning
5025 && !TREE_NO_WARNING (field)
5026 && !last_field_was_bitfield
5027 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
5028 DECL_FIELD_BIT_OFFSET (field),
5029 bitsize_unit_node)))
5030 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
5031 "change in a future version of GCC", field);
5033 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
5034 offset of the field. */
5036 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
5037 byte_position (field))
5038 && contains_empty_class_p (TREE_TYPE (field)))
5039 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
5040 "classes to be placed at different locations in a "
5041 "future version of GCC", field);
5043 /* The middle end uses the type of expressions to determine the
5044 possible range of expression values. In order to optimize
5045 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
5046 must be made aware of the width of "i", via its type.
5048 Because C++ does not have integer types of arbitrary width,
5049 we must (for the purposes of the front end) convert from the
5050 type assigned here to the declared type of the bitfield
5051 whenever a bitfield expression is used as an rvalue.
5052 Similarly, when assigning a value to a bitfield, the value
5053 must be converted to the type given the bitfield here. */
5054 if (DECL_C_BIT_FIELD (field))
5056 unsigned HOST_WIDE_INT width;
5057 tree ftype = TREE_TYPE (field);
5058 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
5059 if (width != TYPE_PRECISION (ftype))
5062 = c_build_bitfield_integer_type (width,
5063 TYPE_UNSIGNED (ftype));
5065 = cp_build_qualified_type (TREE_TYPE (field),
5066 TYPE_QUALS (ftype));
5070 /* If we needed additional padding after this field, add it
5076 padding_field = build_decl (input_location,
5080 DECL_BIT_FIELD (padding_field) = 1;
5081 DECL_SIZE (padding_field) = padding;
5082 DECL_CONTEXT (padding_field) = t;
5083 DECL_ARTIFICIAL (padding_field) = 1;
5084 DECL_IGNORED_P (padding_field) = 1;
5085 layout_nonempty_base_or_field (rli, padding_field,
5087 empty_base_offsets);
5090 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
5093 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
5095 /* Make sure that we are on a byte boundary so that the size of
5096 the class without virtual bases will always be a round number
5098 rli->bitpos = round_up_loc (input_location, rli->bitpos, BITS_PER_UNIT);
5099 normalize_rli (rli);
5102 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5104 if (!abi_version_at_least (2))
5105 include_empty_classes(rli);
5107 /* Delete all zero-width bit-fields from the list of fields. Now
5108 that the type is laid out they are no longer important. */
5109 remove_zero_width_bit_fields (t);
5111 /* Create the version of T used for virtual bases. We do not use
5112 make_class_type for this version; this is an artificial type. For
5113 a POD type, we just reuse T. */
5114 if (CLASSTYPE_NON_LAYOUT_POD_P (t) || CLASSTYPE_EMPTY_P (t))
5116 base_t = make_node (TREE_CODE (t));
5118 /* Set the size and alignment for the new type. In G++ 3.2, all
5119 empty classes were considered to have size zero when used as
5121 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
5123 TYPE_SIZE (base_t) = bitsize_zero_node;
5124 TYPE_SIZE_UNIT (base_t) = size_zero_node;
5125 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
5127 "layout of classes derived from empty class %qT "
5128 "may change in a future version of GCC",
5135 /* If the ABI version is not at least two, and the last
5136 field was a bit-field, RLI may not be on a byte
5137 boundary. In particular, rli_size_unit_so_far might
5138 indicate the last complete byte, while rli_size_so_far
5139 indicates the total number of bits used. Therefore,
5140 rli_size_so_far, rather than rli_size_unit_so_far, is
5141 used to compute TYPE_SIZE_UNIT. */
5142 eoc = end_of_class (t, /*include_virtuals_p=*/0);
5143 TYPE_SIZE_UNIT (base_t)
5144 = size_binop (MAX_EXPR,
5146 size_binop (CEIL_DIV_EXPR,
5147 rli_size_so_far (rli),
5148 bitsize_int (BITS_PER_UNIT))),
5151 = size_binop (MAX_EXPR,
5152 rli_size_so_far (rli),
5153 size_binop (MULT_EXPR,
5154 convert (bitsizetype, eoc),
5155 bitsize_int (BITS_PER_UNIT)));
5157 TYPE_ALIGN (base_t) = rli->record_align;
5158 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
5160 /* Copy the fields from T. */
5161 next_field = &TYPE_FIELDS (base_t);
5162 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5163 if (TREE_CODE (field) == FIELD_DECL)
5165 *next_field = build_decl (input_location,
5169 DECL_CONTEXT (*next_field) = base_t;
5170 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
5171 DECL_FIELD_BIT_OFFSET (*next_field)
5172 = DECL_FIELD_BIT_OFFSET (field);
5173 DECL_SIZE (*next_field) = DECL_SIZE (field);
5174 DECL_MODE (*next_field) = DECL_MODE (field);
5175 next_field = &TREE_CHAIN (*next_field);
5178 /* Record the base version of the type. */
5179 CLASSTYPE_AS_BASE (t) = base_t;
5180 TYPE_CONTEXT (base_t) = t;
5183 CLASSTYPE_AS_BASE (t) = t;
5185 /* Every empty class contains an empty class. */
5186 if (CLASSTYPE_EMPTY_P (t))
5187 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
5189 /* Set the TYPE_DECL for this type to contain the right
5190 value for DECL_OFFSET, so that we can use it as part
5191 of a COMPONENT_REF for multiple inheritance. */
5192 layout_decl (TYPE_MAIN_DECL (t), 0);
5194 /* Now fix up any virtual base class types that we left lying
5195 around. We must get these done before we try to lay out the
5196 virtual function table. As a side-effect, this will remove the
5197 base subobject fields. */
5198 layout_virtual_bases (rli, empty_base_offsets);
5200 /* Make sure that empty classes are reflected in RLI at this
5202 include_empty_classes(rli);
5204 /* Make sure not to create any structures with zero size. */
5205 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
5207 build_decl (input_location,
5208 FIELD_DECL, NULL_TREE, char_type_node));
5210 /* Let the back end lay out the type. */
5211 finish_record_layout (rli, /*free_p=*/true);
5213 /* Warn about bases that can't be talked about due to ambiguity. */
5214 warn_about_ambiguous_bases (t);
5216 /* Now that we're done with layout, give the base fields the real types. */
5217 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5218 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
5219 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
5222 splay_tree_delete (empty_base_offsets);
5224 if (CLASSTYPE_EMPTY_P (t)
5225 && tree_int_cst_lt (sizeof_biggest_empty_class,
5226 TYPE_SIZE_UNIT (t)))
5227 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
5230 /* Determine the "key method" for the class type indicated by TYPE,
5231 and set CLASSTYPE_KEY_METHOD accordingly. */
5234 determine_key_method (tree type)
5238 if (TYPE_FOR_JAVA (type)
5239 || processing_template_decl
5240 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
5241 || CLASSTYPE_INTERFACE_KNOWN (type))
5244 /* The key method is the first non-pure virtual function that is not
5245 inline at the point of class definition. On some targets the
5246 key function may not be inline; those targets should not call
5247 this function until the end of the translation unit. */
5248 for (method = TYPE_METHODS (type); method != NULL_TREE;
5249 method = TREE_CHAIN (method))
5250 if (DECL_VINDEX (method) != NULL_TREE
5251 && ! DECL_DECLARED_INLINE_P (method)
5252 && ! DECL_PURE_VIRTUAL_P (method))
5254 CLASSTYPE_KEY_METHOD (type) = method;
5261 /* Perform processing required when the definition of T (a class type)
5265 finish_struct_1 (tree t)
5268 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5269 tree virtuals = NULL_TREE;
5272 if (COMPLETE_TYPE_P (t))
5274 gcc_assert (MAYBE_CLASS_TYPE_P (t));
5275 error ("redefinition of %q#T", t);
5280 /* If this type was previously laid out as a forward reference,
5281 make sure we lay it out again. */
5282 TYPE_SIZE (t) = NULL_TREE;
5283 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
5285 /* Make assumptions about the class; we'll reset the flags if
5287 CLASSTYPE_EMPTY_P (t) = 1;
5288 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
5289 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
5291 /* Do end-of-class semantic processing: checking the validity of the
5292 bases and members and add implicitly generated methods. */
5293 check_bases_and_members (t);
5295 /* Find the key method. */
5296 if (TYPE_CONTAINS_VPTR_P (t))
5298 /* The Itanium C++ ABI permits the key method to be chosen when
5299 the class is defined -- even though the key method so
5300 selected may later turn out to be an inline function. On
5301 some systems (such as ARM Symbian OS) the key method cannot
5302 be determined until the end of the translation unit. On such
5303 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5304 will cause the class to be added to KEYED_CLASSES. Then, in
5305 finish_file we will determine the key method. */
5306 if (targetm.cxx.key_method_may_be_inline ())
5307 determine_key_method (t);
5309 /* If a polymorphic class has no key method, we may emit the vtable
5310 in every translation unit where the class definition appears. */
5311 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
5312 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
5315 /* Layout the class itself. */
5316 layout_class_type (t, &virtuals);
5317 if (CLASSTYPE_AS_BASE (t) != t)
5318 /* We use the base type for trivial assignments, and hence it
5320 compute_record_mode (CLASSTYPE_AS_BASE (t));
5322 virtuals = modify_all_vtables (t, nreverse (virtuals));
5324 /* If necessary, create the primary vtable for this class. */
5325 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
5327 /* We must enter these virtuals into the table. */
5328 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5329 build_primary_vtable (NULL_TREE, t);
5330 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
5331 /* Here we know enough to change the type of our virtual
5332 function table, but we will wait until later this function. */
5333 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
5336 if (TYPE_CONTAINS_VPTR_P (t))
5341 if (BINFO_VTABLE (TYPE_BINFO (t)))
5342 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5343 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5344 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5346 /* Add entries for virtual functions introduced by this class. */
5347 BINFO_VIRTUALS (TYPE_BINFO (t))
5348 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5350 /* Set DECL_VINDEX for all functions declared in this class. */
5351 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5353 fn = TREE_CHAIN (fn),
5354 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5355 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5357 tree fndecl = BV_FN (fn);
5359 if (DECL_THUNK_P (fndecl))
5360 /* A thunk. We should never be calling this entry directly
5361 from this vtable -- we'd use the entry for the non
5362 thunk base function. */
5363 DECL_VINDEX (fndecl) = NULL_TREE;
5364 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5365 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5369 finish_struct_bits (t);
5371 /* Complete the rtl for any static member objects of the type we're
5373 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5374 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5375 && TREE_TYPE (x) != error_mark_node
5376 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5377 DECL_MODE (x) = TYPE_MODE (t);
5379 /* Done with FIELDS...now decide whether to sort these for
5380 faster lookups later.
5382 We use a small number because most searches fail (succeeding
5383 ultimately as the search bores through the inheritance
5384 hierarchy), and we want this failure to occur quickly. */
5386 n_fields = count_fields (TYPE_FIELDS (t));
5389 struct sorted_fields_type *field_vec = GGC_NEWVAR
5390 (struct sorted_fields_type,
5391 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5392 field_vec->len = n_fields;
5393 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5394 qsort (field_vec->elts, n_fields, sizeof (tree),
5396 CLASSTYPE_SORTED_FIELDS (t) = field_vec;
5399 /* Complain if one of the field types requires lower visibility. */
5400 constrain_class_visibility (t);
5402 /* Make the rtl for any new vtables we have created, and unmark
5403 the base types we marked. */
5406 /* Build the VTT for T. */
5409 /* This warning does not make sense for Java classes, since they
5410 cannot have destructors. */
5411 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5415 dtor = CLASSTYPE_DESTRUCTORS (t);
5416 if (/* An implicitly declared destructor is always public. And,
5417 if it were virtual, we would have created it by now. */
5419 || (!DECL_VINDEX (dtor)
5420 && (/* public non-virtual */
5421 (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
5422 || (/* non-public non-virtual with friends */
5423 (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
5424 && (CLASSTYPE_FRIEND_CLASSES (t)
5425 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
5426 warning (OPT_Wnon_virtual_dtor,
5427 "%q#T has virtual functions and accessible"
5428 " non-virtual destructor", t);
5433 if (warn_overloaded_virtual)
5436 /* Class layout, assignment of virtual table slots, etc., is now
5437 complete. Give the back end a chance to tweak the visibility of
5438 the class or perform any other required target modifications. */
5439 targetm.cxx.adjust_class_at_definition (t);
5441 maybe_suppress_debug_info (t);
5443 dump_class_hierarchy (t);
5445 /* Finish debugging output for this type. */
5446 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5449 /* When T was built up, the member declarations were added in reverse
5450 order. Rearrange them to declaration order. */
5453 unreverse_member_declarations (tree t)
5459 /* The following lists are all in reverse order. Put them in
5460 declaration order now. */
5461 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5462 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5464 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5465 reverse order, so we can't just use nreverse. */
5467 for (x = TYPE_FIELDS (t);
5468 x && TREE_CODE (x) != TYPE_DECL;
5471 next = TREE_CHAIN (x);
5472 TREE_CHAIN (x) = prev;
5477 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5479 TYPE_FIELDS (t) = prev;
5484 finish_struct (tree t, tree attributes)
5486 location_t saved_loc = input_location;
5488 /* Now that we've got all the field declarations, reverse everything
5490 unreverse_member_declarations (t);
5492 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5494 /* Nadger the current location so that diagnostics point to the start of
5495 the struct, not the end. */
5496 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5498 if (processing_template_decl)
5502 finish_struct_methods (t);
5503 TYPE_SIZE (t) = bitsize_zero_node;
5504 TYPE_SIZE_UNIT (t) = size_zero_node;
5506 /* We need to emit an error message if this type was used as a parameter
5507 and it is an abstract type, even if it is a template. We construct
5508 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5509 account and we call complete_vars with this type, which will check
5510 the PARM_DECLS. Note that while the type is being defined,
5511 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5512 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5513 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5514 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5515 if (DECL_PURE_VIRTUAL_P (x))
5516 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5520 finish_struct_1 (t);
5522 input_location = saved_loc;
5524 TYPE_BEING_DEFINED (t) = 0;
5526 if (current_class_type)
5529 error ("trying to finish struct, but kicked out due to previous parse errors");
5531 if (processing_template_decl && at_function_scope_p ())
5532 add_stmt (build_min (TAG_DEFN, t));
5537 /* Return the dynamic type of INSTANCE, if known.
5538 Used to determine whether the virtual function table is needed
5541 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5542 of our knowledge of its type. *NONNULL should be initialized
5543 before this function is called. */
5546 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp)
5548 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5550 switch (TREE_CODE (instance))
5553 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5556 return RECUR (TREE_OPERAND (instance, 0));
5559 /* This is a call to a constructor, hence it's never zero. */
5560 if (TREE_HAS_CONSTRUCTOR (instance))
5564 return TREE_TYPE (instance);
5569 /* This is a call to a constructor, hence it's never zero. */
5570 if (TREE_HAS_CONSTRUCTOR (instance))
5574 return TREE_TYPE (instance);
5576 return RECUR (TREE_OPERAND (instance, 0));
5578 case POINTER_PLUS_EXPR:
5581 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5582 return RECUR (TREE_OPERAND (instance, 0));
5583 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5584 /* Propagate nonnull. */
5585 return RECUR (TREE_OPERAND (instance, 0));
5590 return RECUR (TREE_OPERAND (instance, 0));
5593 instance = TREE_OPERAND (instance, 0);
5596 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5597 with a real object -- given &p->f, p can still be null. */
5598 tree t = get_base_address (instance);
5599 /* ??? Probably should check DECL_WEAK here. */
5600 if (t && DECL_P (t))
5603 return RECUR (instance);
5606 /* If this component is really a base class reference, then the field
5607 itself isn't definitive. */
5608 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5609 return RECUR (TREE_OPERAND (instance, 0));
5610 return RECUR (TREE_OPERAND (instance, 1));
5614 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5615 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
5619 return TREE_TYPE (TREE_TYPE (instance));
5621 /* fall through... */
5625 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance)))
5629 return TREE_TYPE (instance);
5631 else if (instance == current_class_ptr)
5636 /* if we're in a ctor or dtor, we know our type. */
5637 if (DECL_LANG_SPECIFIC (current_function_decl)
5638 && (DECL_CONSTRUCTOR_P (current_function_decl)
5639 || DECL_DESTRUCTOR_P (current_function_decl)))
5643 return TREE_TYPE (TREE_TYPE (instance));
5646 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5648 /* We only need one hash table because it is always left empty. */
5651 ht = htab_create (37,
5656 /* Reference variables should be references to objects. */
5660 /* Enter the INSTANCE in a table to prevent recursion; a
5661 variable's initializer may refer to the variable
5663 if (TREE_CODE (instance) == VAR_DECL
5664 && DECL_INITIAL (instance)
5665 && !htab_find (ht, instance))
5670 slot = htab_find_slot (ht, instance, INSERT);
5672 type = RECUR (DECL_INITIAL (instance));
5673 htab_remove_elt (ht, instance);
5686 /* Return nonzero if the dynamic type of INSTANCE is known, and
5687 equivalent to the static type. We also handle the case where
5688 INSTANCE is really a pointer. Return negative if this is a
5689 ctor/dtor. There the dynamic type is known, but this might not be
5690 the most derived base of the original object, and hence virtual
5691 bases may not be layed out according to this type.
5693 Used to determine whether the virtual function table is needed
5696 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5697 of our knowledge of its type. *NONNULL should be initialized
5698 before this function is called. */
5701 resolves_to_fixed_type_p (tree instance, int* nonnull)
5703 tree t = TREE_TYPE (instance);
5705 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5706 if (fixed == NULL_TREE)
5708 if (POINTER_TYPE_P (t))
5710 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5712 return cdtorp ? -1 : 1;
5717 init_class_processing (void)
5719 current_class_depth = 0;
5720 current_class_stack_size = 10;
5722 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5723 local_classes = VEC_alloc (tree, gc, 8);
5724 sizeof_biggest_empty_class = size_zero_node;
5726 ridpointers[(int) RID_PUBLIC] = access_public_node;
5727 ridpointers[(int) RID_PRIVATE] = access_private_node;
5728 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5731 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5734 restore_class_cache (void)
5738 /* We are re-entering the same class we just left, so we don't
5739 have to search the whole inheritance matrix to find all the
5740 decls to bind again. Instead, we install the cached
5741 class_shadowed list and walk through it binding names. */
5742 push_binding_level (previous_class_level);
5743 class_binding_level = previous_class_level;
5744 /* Restore IDENTIFIER_TYPE_VALUE. */
5745 for (type = class_binding_level->type_shadowed;
5747 type = TREE_CHAIN (type))
5748 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5751 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5752 appropriate for TYPE.
5754 So that we may avoid calls to lookup_name, we cache the _TYPE
5755 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5757 For multiple inheritance, we perform a two-pass depth-first search
5758 of the type lattice. */
5761 pushclass (tree type)
5763 class_stack_node_t csn;
5765 type = TYPE_MAIN_VARIANT (type);
5767 /* Make sure there is enough room for the new entry on the stack. */
5768 if (current_class_depth + 1 >= current_class_stack_size)
5770 current_class_stack_size *= 2;
5772 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5773 current_class_stack_size);
5776 /* Insert a new entry on the class stack. */
5777 csn = current_class_stack + current_class_depth;
5778 csn->name = current_class_name;
5779 csn->type = current_class_type;
5780 csn->access = current_access_specifier;
5781 csn->names_used = 0;
5783 current_class_depth++;
5785 /* Now set up the new type. */
5786 current_class_name = TYPE_NAME (type);
5787 if (TREE_CODE (current_class_name) == TYPE_DECL)
5788 current_class_name = DECL_NAME (current_class_name);
5789 current_class_type = type;
5791 /* By default, things in classes are private, while things in
5792 structures or unions are public. */
5793 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5794 ? access_private_node
5795 : access_public_node);
5797 if (previous_class_level
5798 && type != previous_class_level->this_entity
5799 && current_class_depth == 1)
5801 /* Forcibly remove any old class remnants. */
5802 invalidate_class_lookup_cache ();
5805 if (!previous_class_level
5806 || type != previous_class_level->this_entity
5807 || current_class_depth > 1)
5810 restore_class_cache ();
5813 /* When we exit a toplevel class scope, we save its binding level so
5814 that we can restore it quickly. Here, we've entered some other
5815 class, so we must invalidate our cache. */
5818 invalidate_class_lookup_cache (void)
5820 previous_class_level = NULL;
5823 /* Get out of the current class scope. If we were in a class scope
5824 previously, that is the one popped to. */
5831 current_class_depth--;
5832 current_class_name = current_class_stack[current_class_depth].name;
5833 current_class_type = current_class_stack[current_class_depth].type;
5834 current_access_specifier = current_class_stack[current_class_depth].access;
5835 if (current_class_stack[current_class_depth].names_used)
5836 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5839 /* Mark the top of the class stack as hidden. */
5842 push_class_stack (void)
5844 if (current_class_depth)
5845 ++current_class_stack[current_class_depth - 1].hidden;
5848 /* Mark the top of the class stack as un-hidden. */
5851 pop_class_stack (void)
5853 if (current_class_depth)
5854 --current_class_stack[current_class_depth - 1].hidden;
5857 /* Returns 1 if the class type currently being defined is either T or
5858 a nested type of T. */
5861 currently_open_class (tree t)
5865 if (!CLASS_TYPE_P (t))
5868 t = TYPE_MAIN_VARIANT (t);
5870 /* We start looking from 1 because entry 0 is from global scope,
5872 for (i = current_class_depth; i > 0; --i)
5875 if (i == current_class_depth)
5876 c = current_class_type;
5879 if (current_class_stack[i].hidden)
5881 c = current_class_stack[i].type;
5885 if (same_type_p (c, t))
5891 /* If either current_class_type or one of its enclosing classes are derived
5892 from T, return the appropriate type. Used to determine how we found
5893 something via unqualified lookup. */
5896 currently_open_derived_class (tree t)
5900 /* The bases of a dependent type are unknown. */
5901 if (dependent_type_p (t))
5904 if (!current_class_type)
5907 if (DERIVED_FROM_P (t, current_class_type))
5908 return current_class_type;
5910 for (i = current_class_depth - 1; i > 0; --i)
5912 if (current_class_stack[i].hidden)
5914 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5915 return current_class_stack[i].type;
5921 /* When entering a class scope, all enclosing class scopes' names with
5922 static meaning (static variables, static functions, types and
5923 enumerators) have to be visible. This recursive function calls
5924 pushclass for all enclosing class contexts until global or a local
5925 scope is reached. TYPE is the enclosed class. */
5928 push_nested_class (tree type)
5930 /* A namespace might be passed in error cases, like A::B:C. */
5931 if (type == NULL_TREE
5932 || !CLASS_TYPE_P (type))
5935 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type)));
5940 /* Undoes a push_nested_class call. */
5943 pop_nested_class (void)
5945 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5948 if (context && CLASS_TYPE_P (context))
5949 pop_nested_class ();
5952 /* Returns the number of extern "LANG" blocks we are nested within. */
5955 current_lang_depth (void)
5957 return VEC_length (tree, current_lang_base);
5960 /* Set global variables CURRENT_LANG_NAME to appropriate value
5961 so that behavior of name-mangling machinery is correct. */
5964 push_lang_context (tree name)
5966 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5968 if (name == lang_name_cplusplus)
5970 current_lang_name = name;
5972 else if (name == lang_name_java)
5974 current_lang_name = name;
5975 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5976 (See record_builtin_java_type in decl.c.) However, that causes
5977 incorrect debug entries if these types are actually used.
5978 So we re-enable debug output after extern "Java". */
5979 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5980 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5981 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5982 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5983 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5984 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5985 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5986 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5988 else if (name == lang_name_c)
5990 current_lang_name = name;
5993 error ("language string %<\"%E\"%> not recognized", name);
5996 /* Get out of the current language scope. */
5999 pop_lang_context (void)
6001 current_lang_name = VEC_pop (tree, current_lang_base);
6004 /* Type instantiation routines. */
6006 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
6007 matches the TARGET_TYPE. If there is no satisfactory match, return
6008 error_mark_node, and issue an error & warning messages under
6009 control of FLAGS. Permit pointers to member function if FLAGS
6010 permits. If TEMPLATE_ONLY, the name of the overloaded function was
6011 a template-id, and EXPLICIT_TARGS are the explicitly provided
6014 If OVERLOAD is for one or more member functions, then ACCESS_PATH
6015 is the base path used to reference those member functions. If
6016 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
6017 resolved to a member function, access checks will be performed and
6018 errors issued if appropriate. */
6021 resolve_address_of_overloaded_function (tree target_type,
6023 tsubst_flags_t flags,
6025 tree explicit_targs,
6028 /* Here's what the standard says:
6032 If the name is a function template, template argument deduction
6033 is done, and if the argument deduction succeeds, the deduced
6034 arguments are used to generate a single template function, which
6035 is added to the set of overloaded functions considered.
6037 Non-member functions and static member functions match targets of
6038 type "pointer-to-function" or "reference-to-function." Nonstatic
6039 member functions match targets of type "pointer-to-member
6040 function;" the function type of the pointer to member is used to
6041 select the member function from the set of overloaded member
6042 functions. If a nonstatic member function is selected, the
6043 reference to the overloaded function name is required to have the
6044 form of a pointer to member as described in 5.3.1.
6046 If more than one function is selected, any template functions in
6047 the set are eliminated if the set also contains a non-template
6048 function, and any given template function is eliminated if the
6049 set contains a second template function that is more specialized
6050 than the first according to the partial ordering rules 14.5.5.2.
6051 After such eliminations, if any, there shall remain exactly one
6052 selected function. */
6055 int is_reference = 0;
6056 /* We store the matches in a TREE_LIST rooted here. The functions
6057 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
6058 interoperability with most_specialized_instantiation. */
6059 tree matches = NULL_TREE;
6062 /* By the time we get here, we should be seeing only real
6063 pointer-to-member types, not the internal POINTER_TYPE to
6064 METHOD_TYPE representation. */
6065 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
6066 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
6068 gcc_assert (is_overloaded_fn (overload));
6070 /* Check that the TARGET_TYPE is reasonable. */
6071 if (TYPE_PTRFN_P (target_type))
6073 else if (TYPE_PTRMEMFUNC_P (target_type))
6074 /* This is OK, too. */
6076 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
6078 /* This is OK, too. This comes from a conversion to reference
6080 target_type = build_reference_type (target_type);
6085 if (flags & tf_error)
6086 error ("cannot resolve overloaded function %qD based on"
6087 " conversion to type %qT",
6088 DECL_NAME (OVL_FUNCTION (overload)), target_type);
6089 return error_mark_node;
6092 /* If we can find a non-template function that matches, we can just
6093 use it. There's no point in generating template instantiations
6094 if we're just going to throw them out anyhow. But, of course, we
6095 can only do this when we don't *need* a template function. */
6100 for (fns = overload; fns; fns = OVL_NEXT (fns))
6102 tree fn = OVL_CURRENT (fns);
6105 if (TREE_CODE (fn) == TEMPLATE_DECL)
6106 /* We're not looking for templates just yet. */
6109 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6111 /* We're looking for a non-static member, and this isn't
6112 one, or vice versa. */
6115 /* Ignore functions which haven't been explicitly
6117 if (DECL_ANTICIPATED (fn))
6120 /* See if there's a match. */
6121 fntype = TREE_TYPE (fn);
6123 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
6124 else if (!is_reference)
6125 fntype = build_pointer_type (fntype);
6127 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
6128 matches = tree_cons (fn, NULL_TREE, matches);
6132 /* Now, if we've already got a match (or matches), there's no need
6133 to proceed to the template functions. But, if we don't have a
6134 match we need to look at them, too. */
6137 tree target_fn_type;
6138 tree target_arg_types;
6139 tree target_ret_type;
6142 unsigned int nargs, ia;
6147 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
6149 target_fn_type = TREE_TYPE (target_type);
6150 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
6151 target_ret_type = TREE_TYPE (target_fn_type);
6153 /* Never do unification on the 'this' parameter. */
6154 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
6155 target_arg_types = TREE_CHAIN (target_arg_types);
6157 nargs = list_length (target_arg_types);
6158 args = XALLOCAVEC (tree, nargs);
6159 for (arg = target_arg_types, ia = 0;
6160 arg != NULL_TREE && arg != void_list_node;
6161 arg = TREE_CHAIN (arg), ++ia)
6162 args[ia] = TREE_VALUE (arg);
6165 for (fns = overload; fns; fns = OVL_NEXT (fns))
6167 tree fn = OVL_CURRENT (fns);
6169 tree instantiation_type;
6172 if (TREE_CODE (fn) != TEMPLATE_DECL)
6173 /* We're only looking for templates. */
6176 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6178 /* We're not looking for a non-static member, and this is
6179 one, or vice versa. */
6182 /* Try to do argument deduction. */
6183 targs = make_tree_vec (DECL_NTPARMS (fn));
6184 if (fn_type_unification (fn, explicit_targs, targs, args, nargs,
6185 target_ret_type, DEDUCE_EXACT,
6187 /* Argument deduction failed. */
6190 /* Instantiate the template. */
6191 instantiation = instantiate_template (fn, targs, flags);
6192 if (instantiation == error_mark_node)
6193 /* Instantiation failed. */
6196 /* See if there's a match. */
6197 instantiation_type = TREE_TYPE (instantiation);
6199 instantiation_type =
6200 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
6201 else if (!is_reference)
6202 instantiation_type = build_pointer_type (instantiation_type);
6203 if (can_convert_arg (target_type, instantiation_type, instantiation,
6205 matches = tree_cons (instantiation, fn, matches);
6208 /* Now, remove all but the most specialized of the matches. */
6211 tree match = most_specialized_instantiation (matches);
6213 if (match != error_mark_node)
6214 matches = tree_cons (TREE_PURPOSE (match),
6220 /* Now we should have exactly one function in MATCHES. */
6221 if (matches == NULL_TREE)
6223 /* There were *no* matches. */
6224 if (flags & tf_error)
6226 error ("no matches converting function %qD to type %q#T",
6227 DECL_NAME (OVL_CURRENT (overload)),
6230 /* print_candidates expects a chain with the functions in
6231 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6232 so why be clever?). */
6233 for (; overload; overload = OVL_NEXT (overload))
6234 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
6237 print_candidates (matches);
6239 return error_mark_node;
6241 else if (TREE_CHAIN (matches))
6243 /* There were too many matches. First check if they're all
6244 the same function. */
6247 fn = TREE_PURPOSE (matches);
6248 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match))
6249 if (!decls_match (fn, TREE_PURPOSE (match)))
6254 if (flags & tf_error)
6256 error ("converting overloaded function %qD to type %q#T is ambiguous",
6257 DECL_NAME (OVL_FUNCTION (overload)),
6260 /* Since print_candidates expects the functions in the
6261 TREE_VALUE slot, we flip them here. */
6262 for (match = matches; match; match = TREE_CHAIN (match))
6263 TREE_VALUE (match) = TREE_PURPOSE (match);
6265 print_candidates (matches);
6268 return error_mark_node;
6272 /* Good, exactly one match. Now, convert it to the correct type. */
6273 fn = TREE_PURPOSE (matches);
6275 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
6276 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
6278 static int explained;
6280 if (!(flags & tf_error))
6281 return error_mark_node;
6283 permerror (input_location, "assuming pointer to member %qD", fn);
6286 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn);
6291 /* If we're doing overload resolution purely for the purpose of
6292 determining conversion sequences, we should not consider the
6293 function used. If this conversion sequence is selected, the
6294 function will be marked as used at this point. */
6295 if (!(flags & tf_conv))
6297 /* Make =delete work with SFINAE. */
6298 if (DECL_DELETED_FN (fn) && !(flags & tf_error))
6299 return error_mark_node;
6304 /* We could not check access to member functions when this
6305 expression was originally created since we did not know at that
6306 time to which function the expression referred. */
6307 if (!(flags & tf_no_access_control)
6308 && DECL_FUNCTION_MEMBER_P (fn))
6310 gcc_assert (access_path);
6311 perform_or_defer_access_check (access_path, fn, fn);
6314 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
6315 return cp_build_unary_op (ADDR_EXPR, fn, 0, flags);
6318 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6319 will mark the function as addressed, but here we must do it
6321 cxx_mark_addressable (fn);
6327 /* This function will instantiate the type of the expression given in
6328 RHS to match the type of LHSTYPE. If errors exist, then return
6329 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6330 we complain on errors. If we are not complaining, never modify rhs,
6331 as overload resolution wants to try many possible instantiations, in
6332 the hope that at least one will work.
6334 For non-recursive calls, LHSTYPE should be a function, pointer to
6335 function, or a pointer to member function. */
6338 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
6340 tsubst_flags_t flags_in = flags;
6341 tree access_path = NULL_TREE;
6343 flags &= ~tf_ptrmem_ok;
6345 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
6347 if (flags & tf_error)
6348 error ("not enough type information");
6349 return error_mark_node;
6352 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
6354 if (same_type_p (lhstype, TREE_TYPE (rhs)))
6356 if (flag_ms_extensions
6357 && TYPE_PTRMEMFUNC_P (lhstype)
6358 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
6359 /* Microsoft allows `A::f' to be resolved to a
6360 pointer-to-member. */
6364 if (flags & tf_error)
6365 error ("argument of type %qT does not match %qT",
6366 TREE_TYPE (rhs), lhstype);
6367 return error_mark_node;
6371 if (TREE_CODE (rhs) == BASELINK)
6373 access_path = BASELINK_ACCESS_BINFO (rhs);
6374 rhs = BASELINK_FUNCTIONS (rhs);
6377 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6378 deduce any type information. */
6379 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
6381 if (flags & tf_error)
6382 error ("not enough type information");
6383 return error_mark_node;
6386 /* There only a few kinds of expressions that may have a type
6387 dependent on overload resolution. */
6388 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
6389 || TREE_CODE (rhs) == COMPONENT_REF
6390 || really_overloaded_fn (rhs)
6391 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL));
6393 /* This should really only be used when attempting to distinguish
6394 what sort of a pointer to function we have. For now, any
6395 arithmetic operation which is not supported on pointers
6396 is rejected as an error. */
6398 switch (TREE_CODE (rhs))
6402 tree member = TREE_OPERAND (rhs, 1);
6404 member = instantiate_type (lhstype, member, flags);
6405 if (member != error_mark_node
6406 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6407 /* Do not lose object's side effects. */
6408 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6409 TREE_OPERAND (rhs, 0), member);
6414 rhs = TREE_OPERAND (rhs, 1);
6415 if (BASELINK_P (rhs))
6416 return instantiate_type (lhstype, rhs, flags_in);
6418 /* This can happen if we are forming a pointer-to-member for a
6420 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6424 case TEMPLATE_ID_EXPR:
6426 tree fns = TREE_OPERAND (rhs, 0);
6427 tree args = TREE_OPERAND (rhs, 1);
6430 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6431 /*template_only=*/true,
6438 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6439 /*template_only=*/false,
6440 /*explicit_targs=*/NULL_TREE,
6445 if (PTRMEM_OK_P (rhs))
6446 flags |= tf_ptrmem_ok;
6448 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6452 return error_mark_node;
6457 return error_mark_node;
6460 /* Return the name of the virtual function pointer field
6461 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6462 this may have to look back through base types to find the
6463 ultimate field name. (For single inheritance, these could
6464 all be the same name. Who knows for multiple inheritance). */
6467 get_vfield_name (tree type)
6469 tree binfo, base_binfo;
6472 for (binfo = TYPE_BINFO (type);
6473 BINFO_N_BASE_BINFOS (binfo);
6476 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6478 if (BINFO_VIRTUAL_P (base_binfo)
6479 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6483 type = BINFO_TYPE (binfo);
6484 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
6485 + TYPE_NAME_LENGTH (type) + 2);
6486 sprintf (buf, VFIELD_NAME_FORMAT,
6487 IDENTIFIER_POINTER (constructor_name (type)));
6488 return get_identifier (buf);
6492 print_class_statistics (void)
6494 #ifdef GATHER_STATISTICS
6495 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6496 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6499 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6500 n_vtables, n_vtable_searches);
6501 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6502 n_vtable_entries, n_vtable_elems);
6507 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6508 according to [class]:
6509 The class-name is also inserted
6510 into the scope of the class itself. For purposes of access checking,
6511 the inserted class name is treated as if it were a public member name. */
6514 build_self_reference (void)
6516 tree name = constructor_name (current_class_type);
6517 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6520 DECL_NONLOCAL (value) = 1;
6521 DECL_CONTEXT (value) = current_class_type;
6522 DECL_ARTIFICIAL (value) = 1;
6523 SET_DECL_SELF_REFERENCE_P (value);
6525 if (processing_template_decl)
6526 value = push_template_decl (value);
6528 saved_cas = current_access_specifier;
6529 current_access_specifier = access_public_node;
6530 finish_member_declaration (value);
6531 current_access_specifier = saved_cas;
6534 /* Returns 1 if TYPE contains only padding bytes. */
6537 is_empty_class (tree type)
6539 if (type == error_mark_node)
6542 if (! CLASS_TYPE_P (type))
6545 /* In G++ 3.2, whether or not a class was empty was determined by
6546 looking at its size. */
6547 if (abi_version_at_least (2))
6548 return CLASSTYPE_EMPTY_P (type);
6550 return integer_zerop (CLASSTYPE_SIZE (type));
6553 /* Returns true if TYPE contains an empty class. */
6556 contains_empty_class_p (tree type)
6558 if (is_empty_class (type))
6560 if (CLASS_TYPE_P (type))
6567 for (binfo = TYPE_BINFO (type), i = 0;
6568 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6569 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6571 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6572 if (TREE_CODE (field) == FIELD_DECL
6573 && !DECL_ARTIFICIAL (field)
6574 && is_empty_class (TREE_TYPE (field)))
6577 else if (TREE_CODE (type) == ARRAY_TYPE)
6578 return contains_empty_class_p (TREE_TYPE (type));
6582 /* Returns true if TYPE contains no actual data, just various
6583 possible combinations of empty classes. */
6586 is_really_empty_class (tree type)
6588 if (is_empty_class (type))
6590 if (CLASS_TYPE_P (type))
6597 for (binfo = TYPE_BINFO (type), i = 0;
6598 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6599 if (!is_really_empty_class (BINFO_TYPE (base_binfo)))
6601 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6602 if (TREE_CODE (field) == FIELD_DECL
6603 && !DECL_ARTIFICIAL (field)
6604 && !is_really_empty_class (TREE_TYPE (field)))
6608 else if (TREE_CODE (type) == ARRAY_TYPE)
6609 return is_really_empty_class (TREE_TYPE (type));
6613 /* Note that NAME was looked up while the current class was being
6614 defined and that the result of that lookup was DECL. */
6617 maybe_note_name_used_in_class (tree name, tree decl)
6619 splay_tree names_used;
6621 /* If we're not defining a class, there's nothing to do. */
6622 if (!(innermost_scope_kind() == sk_class
6623 && TYPE_BEING_DEFINED (current_class_type)
6624 && !LAMBDA_TYPE_P (current_class_type)))
6627 /* If there's already a binding for this NAME, then we don't have
6628 anything to worry about. */
6629 if (lookup_member (current_class_type, name,
6630 /*protect=*/0, /*want_type=*/false))
6633 if (!current_class_stack[current_class_depth - 1].names_used)
6634 current_class_stack[current_class_depth - 1].names_used
6635 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6636 names_used = current_class_stack[current_class_depth - 1].names_used;
6638 splay_tree_insert (names_used,
6639 (splay_tree_key) name,
6640 (splay_tree_value) decl);
6643 /* Note that NAME was declared (as DECL) in the current class. Check
6644 to see that the declaration is valid. */
6647 note_name_declared_in_class (tree name, tree decl)
6649 splay_tree names_used;
6652 /* Look to see if we ever used this name. */
6654 = current_class_stack[current_class_depth - 1].names_used;
6658 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6661 /* [basic.scope.class]
6663 A name N used in a class S shall refer to the same declaration
6664 in its context and when re-evaluated in the completed scope of
6666 permerror (input_location, "declaration of %q#D", decl);
6667 permerror (input_location, "changes meaning of %qD from %q+#D",
6668 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6672 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6673 Secondary vtables are merged with primary vtables; this function
6674 will return the VAR_DECL for the primary vtable. */
6677 get_vtbl_decl_for_binfo (tree binfo)
6681 decl = BINFO_VTABLE (binfo);
6682 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR)
6684 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6685 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6688 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6693 /* Returns the binfo for the primary base of BINFO. If the resulting
6694 BINFO is a virtual base, and it is inherited elsewhere in the
6695 hierarchy, then the returned binfo might not be the primary base of
6696 BINFO in the complete object. Check BINFO_PRIMARY_P or
6697 BINFO_LOST_PRIMARY_P to be sure. */
6700 get_primary_binfo (tree binfo)
6704 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6708 return copied_binfo (primary_base, binfo);
6711 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6714 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6717 fprintf (stream, "%*s", indent, "");
6721 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6722 INDENT should be zero when called from the top level; it is
6723 incremented recursively. IGO indicates the next expected BINFO in
6724 inheritance graph ordering. */
6727 dump_class_hierarchy_r (FILE *stream,
6737 indented = maybe_indent_hierarchy (stream, indent, 0);
6738 fprintf (stream, "%s (0x%lx) ",
6739 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6740 (unsigned long) binfo);
6743 fprintf (stream, "alternative-path\n");
6746 igo = TREE_CHAIN (binfo);
6748 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6749 tree_low_cst (BINFO_OFFSET (binfo), 0));
6750 if (is_empty_class (BINFO_TYPE (binfo)))
6751 fprintf (stream, " empty");
6752 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6753 fprintf (stream, " nearly-empty");
6754 if (BINFO_VIRTUAL_P (binfo))
6755 fprintf (stream, " virtual");
6756 fprintf (stream, "\n");
6759 if (BINFO_PRIMARY_P (binfo))
6761 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6762 fprintf (stream, " primary-for %s (0x%lx)",
6763 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6764 TFF_PLAIN_IDENTIFIER),
6765 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6767 if (BINFO_LOST_PRIMARY_P (binfo))
6769 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6770 fprintf (stream, " lost-primary");
6773 fprintf (stream, "\n");
6775 if (!(flags & TDF_SLIM))
6779 if (BINFO_SUBVTT_INDEX (binfo))
6781 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6782 fprintf (stream, " subvttidx=%s",
6783 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6784 TFF_PLAIN_IDENTIFIER));
6786 if (BINFO_VPTR_INDEX (binfo))
6788 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6789 fprintf (stream, " vptridx=%s",
6790 expr_as_string (BINFO_VPTR_INDEX (binfo),
6791 TFF_PLAIN_IDENTIFIER));
6793 if (BINFO_VPTR_FIELD (binfo))
6795 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6796 fprintf (stream, " vbaseoffset=%s",
6797 expr_as_string (BINFO_VPTR_FIELD (binfo),
6798 TFF_PLAIN_IDENTIFIER));
6800 if (BINFO_VTABLE (binfo))
6802 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6803 fprintf (stream, " vptr=%s",
6804 expr_as_string (BINFO_VTABLE (binfo),
6805 TFF_PLAIN_IDENTIFIER));
6809 fprintf (stream, "\n");
6812 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6813 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6818 /* Dump the BINFO hierarchy for T. */
6821 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6823 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6824 fprintf (stream, " size=%lu align=%lu\n",
6825 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6826 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6827 fprintf (stream, " base size=%lu base align=%lu\n",
6828 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6830 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6832 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6833 fprintf (stream, "\n");
6836 /* Debug interface to hierarchy dumping. */
6839 debug_class (tree t)
6841 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6845 dump_class_hierarchy (tree t)
6848 FILE *stream = dump_begin (TDI_class, &flags);
6852 dump_class_hierarchy_1 (stream, flags, t);
6853 dump_end (TDI_class, stream);
6858 dump_array (FILE * stream, tree decl)
6861 unsigned HOST_WIDE_INT ix;
6863 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6865 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6867 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6868 fprintf (stream, " %s entries",
6869 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6870 TFF_PLAIN_IDENTIFIER));
6871 fprintf (stream, "\n");
6873 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6875 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6876 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6880 dump_vtable (tree t, tree binfo, tree vtable)
6883 FILE *stream = dump_begin (TDI_class, &flags);
6888 if (!(flags & TDF_SLIM))
6890 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6892 fprintf (stream, "%s for %s",
6893 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6894 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6897 if (!BINFO_VIRTUAL_P (binfo))
6898 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6899 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6901 fprintf (stream, "\n");
6902 dump_array (stream, vtable);
6903 fprintf (stream, "\n");
6906 dump_end (TDI_class, stream);
6910 dump_vtt (tree t, tree vtt)
6913 FILE *stream = dump_begin (TDI_class, &flags);
6918 if (!(flags & TDF_SLIM))
6920 fprintf (stream, "VTT for %s\n",
6921 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6922 dump_array (stream, vtt);
6923 fprintf (stream, "\n");
6926 dump_end (TDI_class, stream);
6929 /* Dump a function or thunk and its thunkees. */
6932 dump_thunk (FILE *stream, int indent, tree thunk)
6934 static const char spaces[] = " ";
6935 tree name = DECL_NAME (thunk);
6938 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6940 !DECL_THUNK_P (thunk) ? "function"
6941 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6942 name ? IDENTIFIER_POINTER (name) : "<unset>");
6943 if (DECL_THUNK_P (thunk))
6945 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6946 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6948 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6949 if (!virtual_adjust)
6951 else if (DECL_THIS_THUNK_P (thunk))
6952 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6953 tree_low_cst (virtual_adjust, 0));
6955 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6956 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6957 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6958 if (THUNK_ALIAS (thunk))
6959 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6961 fprintf (stream, "\n");
6962 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6963 dump_thunk (stream, indent + 2, thunks);
6966 /* Dump the thunks for FN. */
6969 debug_thunks (tree fn)
6971 dump_thunk (stderr, 0, fn);
6974 /* Virtual function table initialization. */
6976 /* Create all the necessary vtables for T and its base classes. */
6979 finish_vtbls (tree t)
6984 /* We lay out the primary and secondary vtables in one contiguous
6985 vtable. The primary vtable is first, followed by the non-virtual
6986 secondary vtables in inheritance graph order. */
6987 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6988 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6989 TYPE_BINFO (t), t, list);
6991 /* Then come the virtual bases, also in inheritance graph order. */
6992 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6994 if (!BINFO_VIRTUAL_P (vbase))
6996 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6999 if (BINFO_VTABLE (TYPE_BINFO (t)))
7000 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
7003 /* Initialize the vtable for BINFO with the INITS. */
7006 initialize_vtable (tree binfo, tree inits)
7010 layout_vtable_decl (binfo, list_length (inits));
7011 decl = get_vtbl_decl_for_binfo (binfo);
7012 initialize_artificial_var (decl, inits);
7013 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
7016 /* Build the VTT (virtual table table) for T.
7017 A class requires a VTT if it has virtual bases.
7020 1 - primary virtual pointer for complete object T
7021 2 - secondary VTTs for each direct non-virtual base of T which requires a
7023 3 - secondary virtual pointers for each direct or indirect base of T which
7024 has virtual bases or is reachable via a virtual path from T.
7025 4 - secondary VTTs for each direct or indirect virtual base of T.
7027 Secondary VTTs look like complete object VTTs without part 4. */
7037 /* Build up the initializers for the VTT. */
7039 index = size_zero_node;
7040 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
7042 /* If we didn't need a VTT, we're done. */
7046 /* Figure out the type of the VTT. */
7047 type = build_index_type (size_int (list_length (inits) - 1));
7048 type = build_cplus_array_type (const_ptr_type_node, type);
7050 /* Now, build the VTT object itself. */
7051 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
7052 initialize_artificial_var (vtt, inits);
7053 /* Add the VTT to the vtables list. */
7054 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
7055 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
7060 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7061 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7062 and CHAIN the vtable pointer for this binfo after construction is
7063 complete. VALUE can also be another BINFO, in which case we recurse. */
7066 binfo_ctor_vtable (tree binfo)
7072 vt = BINFO_VTABLE (binfo);
7073 if (TREE_CODE (vt) == TREE_LIST)
7074 vt = TREE_VALUE (vt);
7075 if (TREE_CODE (vt) == TREE_BINFO)
7084 /* Data for secondary VTT initialization. */
7085 typedef struct secondary_vptr_vtt_init_data_s
7087 /* Is this the primary VTT? */
7090 /* Current index into the VTT. */
7093 /* TREE_LIST of initializers built up. */
7096 /* The type being constructed by this secondary VTT. */
7097 tree type_being_constructed;
7098 } secondary_vptr_vtt_init_data;
7100 /* Recursively build the VTT-initializer for BINFO (which is in the
7101 hierarchy dominated by T). INITS points to the end of the initializer
7102 list to date. INDEX is the VTT index where the next element will be
7103 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7104 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7105 for virtual bases of T. When it is not so, we build the constructor
7106 vtables for the BINFO-in-T variant. */
7109 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
7114 tree secondary_vptrs;
7115 secondary_vptr_vtt_init_data data;
7116 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7118 /* We only need VTTs for subobjects with virtual bases. */
7119 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7122 /* We need to use a construction vtable if this is not the primary
7126 build_ctor_vtbl_group (binfo, t);
7128 /* Record the offset in the VTT where this sub-VTT can be found. */
7129 BINFO_SUBVTT_INDEX (binfo) = *index;
7132 /* Add the address of the primary vtable for the complete object. */
7133 init = binfo_ctor_vtable (binfo);
7134 *inits = build_tree_list (NULL_TREE, init);
7135 inits = &TREE_CHAIN (*inits);
7138 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7139 BINFO_VPTR_INDEX (binfo) = *index;
7141 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
7143 /* Recursively add the secondary VTTs for non-virtual bases. */
7144 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
7145 if (!BINFO_VIRTUAL_P (b))
7146 inits = build_vtt_inits (b, t, inits, index);
7148 /* Add secondary virtual pointers for all subobjects of BINFO with
7149 either virtual bases or reachable along a virtual path, except
7150 subobjects that are non-virtual primary bases. */
7151 data.top_level_p = top_level_p;
7152 data.index = *index;
7154 data.type_being_constructed = BINFO_TYPE (binfo);
7156 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
7158 *index = data.index;
7160 /* The secondary vptrs come back in reverse order. After we reverse
7161 them, and add the INITS, the last init will be the first element
7163 secondary_vptrs = data.inits;
7164 if (secondary_vptrs)
7166 *inits = nreverse (secondary_vptrs);
7167 inits = &TREE_CHAIN (secondary_vptrs);
7168 gcc_assert (*inits == NULL_TREE);
7172 /* Add the secondary VTTs for virtual bases in inheritance graph
7174 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
7176 if (!BINFO_VIRTUAL_P (b))
7179 inits = build_vtt_inits (b, t, inits, index);
7182 /* Remove the ctor vtables we created. */
7183 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
7188 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7189 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7192 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
7194 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
7196 /* We don't care about bases that don't have vtables. */
7197 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
7198 return dfs_skip_bases;
7200 /* We're only interested in proper subobjects of the type being
7202 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
7205 /* We're only interested in bases with virtual bases or reachable
7206 via a virtual path from the type being constructed. */
7207 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7208 || binfo_via_virtual (binfo, data->type_being_constructed)))
7209 return dfs_skip_bases;
7211 /* We're not interested in non-virtual primary bases. */
7212 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
7215 /* Record the index where this secondary vptr can be found. */
7216 if (data->top_level_p)
7218 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7219 BINFO_VPTR_INDEX (binfo) = data->index;
7221 if (BINFO_VIRTUAL_P (binfo))
7223 /* It's a primary virtual base, and this is not a
7224 construction vtable. Find the base this is primary of in
7225 the inheritance graph, and use that base's vtable
7227 while (BINFO_PRIMARY_P (binfo))
7228 binfo = BINFO_INHERITANCE_CHAIN (binfo);
7232 /* Add the initializer for the secondary vptr itself. */
7233 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
7235 /* Advance the vtt index. */
7236 data->index = size_binop (PLUS_EXPR, data->index,
7237 TYPE_SIZE_UNIT (ptr_type_node));
7242 /* Called from build_vtt_inits via dfs_walk. After building
7243 constructor vtables and generating the sub-vtt from them, we need
7244 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7245 binfo of the base whose sub vtt was generated. */
7248 dfs_fixup_binfo_vtbls (tree binfo, void* data)
7250 tree vtable = BINFO_VTABLE (binfo);
7252 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7253 /* If this class has no vtable, none of its bases do. */
7254 return dfs_skip_bases;
7257 /* This might be a primary base, so have no vtable in this
7261 /* If we scribbled the construction vtable vptr into BINFO, clear it
7263 if (TREE_CODE (vtable) == TREE_LIST
7264 && (TREE_PURPOSE (vtable) == (tree) data))
7265 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
7270 /* Build the construction vtable group for BINFO which is in the
7271 hierarchy dominated by T. */
7274 build_ctor_vtbl_group (tree binfo, tree t)
7283 /* See if we've already created this construction vtable group. */
7284 id = mangle_ctor_vtbl_for_type (t, binfo);
7285 if (IDENTIFIER_GLOBAL_VALUE (id))
7288 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
7289 /* Build a version of VTBL (with the wrong type) for use in
7290 constructing the addresses of secondary vtables in the
7291 construction vtable group. */
7292 vtbl = build_vtable (t, id, ptr_type_node);
7293 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
7294 list = build_tree_list (vtbl, NULL_TREE);
7295 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
7298 /* Add the vtables for each of our virtual bases using the vbase in T
7300 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7302 vbase = TREE_CHAIN (vbase))
7306 if (!BINFO_VIRTUAL_P (vbase))
7308 b = copied_binfo (vbase, binfo);
7310 accumulate_vtbl_inits (b, vbase, binfo, t, list);
7312 inits = TREE_VALUE (list);
7314 /* Figure out the type of the construction vtable. */
7315 type = build_index_type (size_int (list_length (inits) - 1));
7316 type = build_cplus_array_type (vtable_entry_type, type);
7318 TREE_TYPE (vtbl) = type;
7319 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE;
7320 layout_decl (vtbl, 0);
7322 /* Initialize the construction vtable. */
7323 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
7324 initialize_artificial_var (vtbl, inits);
7325 dump_vtable (t, binfo, vtbl);
7328 /* Add the vtbl initializers for BINFO (and its bases other than
7329 non-virtual primaries) to the list of INITS. BINFO is in the
7330 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7331 the constructor the vtbl inits should be accumulated for. (If this
7332 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7333 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7334 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7335 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7336 but are not necessarily the same in terms of layout. */
7339 accumulate_vtbl_inits (tree binfo,
7347 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7349 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7351 /* If it doesn't have a vptr, we don't do anything. */
7352 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7355 /* If we're building a construction vtable, we're not interested in
7356 subobjects that don't require construction vtables. */
7358 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7359 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7362 /* Build the initializers for the BINFO-in-T vtable. */
7364 = chainon (TREE_VALUE (inits),
7365 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7366 rtti_binfo, t, inits));
7368 /* Walk the BINFO and its bases. We walk in preorder so that as we
7369 initialize each vtable we can figure out at what offset the
7370 secondary vtable lies from the primary vtable. We can't use
7371 dfs_walk here because we need to iterate through bases of BINFO
7372 and RTTI_BINFO simultaneously. */
7373 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7375 /* Skip virtual bases. */
7376 if (BINFO_VIRTUAL_P (base_binfo))
7378 accumulate_vtbl_inits (base_binfo,
7379 BINFO_BASE_BINFO (orig_binfo, i),
7385 /* Called from accumulate_vtbl_inits. Returns the initializers for
7386 the BINFO vtable. */
7389 dfs_accumulate_vtbl_inits (tree binfo,
7395 tree inits = NULL_TREE;
7396 tree vtbl = NULL_TREE;
7397 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7400 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7402 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7403 primary virtual base. If it is not the same primary in
7404 the hierarchy of T, we'll need to generate a ctor vtable
7405 for it, to place at its location in T. If it is the same
7406 primary, we still need a VTT entry for the vtable, but it
7407 should point to the ctor vtable for the base it is a
7408 primary for within the sub-hierarchy of RTTI_BINFO.
7410 There are three possible cases:
7412 1) We are in the same place.
7413 2) We are a primary base within a lost primary virtual base of
7415 3) We are primary to something not a base of RTTI_BINFO. */
7418 tree last = NULL_TREE;
7420 /* First, look through the bases we are primary to for RTTI_BINFO
7421 or a virtual base. */
7423 while (BINFO_PRIMARY_P (b))
7425 b = BINFO_INHERITANCE_CHAIN (b);
7427 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7430 /* If we run out of primary links, keep looking down our
7431 inheritance chain; we might be an indirect primary. */
7432 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7433 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7437 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7438 base B and it is a base of RTTI_BINFO, this is case 2. In
7439 either case, we share our vtable with LAST, i.e. the
7440 derived-most base within B of which we are a primary. */
7442 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7443 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7444 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7445 binfo_ctor_vtable after everything's been set up. */
7448 /* Otherwise, this is case 3 and we get our own. */
7450 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7458 /* Compute the initializer for this vtable. */
7459 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7462 /* Figure out the position to which the VPTR should point. */
7463 vtbl = TREE_PURPOSE (l);
7464 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7465 index = size_binop (PLUS_EXPR,
7466 size_int (non_fn_entries),
7467 size_int (list_length (TREE_VALUE (l))));
7468 index = size_binop (MULT_EXPR,
7469 TYPE_SIZE_UNIT (vtable_entry_type),
7471 vtbl = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7475 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7476 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7477 straighten this out. */
7478 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7479 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7482 /* For an ordinary vtable, set BINFO_VTABLE. */
7483 BINFO_VTABLE (binfo) = vtbl;
7488 static GTY(()) tree abort_fndecl_addr;
7490 /* Construct the initializer for BINFO's virtual function table. BINFO
7491 is part of the hierarchy dominated by T. If we're building a
7492 construction vtable, the ORIG_BINFO is the binfo we should use to
7493 find the actual function pointers to put in the vtable - but they
7494 can be overridden on the path to most-derived in the graph that
7495 ORIG_BINFO belongs. Otherwise,
7496 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7497 BINFO that should be indicated by the RTTI information in the
7498 vtable; it will be a base class of T, rather than T itself, if we
7499 are building a construction vtable.
7501 The value returned is a TREE_LIST suitable for wrapping in a
7502 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7503 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7504 number of non-function entries in the vtable.
7506 It might seem that this function should never be called with a
7507 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7508 base is always subsumed by a derived class vtable. However, when
7509 we are building construction vtables, we do build vtables for
7510 primary bases; we need these while the primary base is being
7514 build_vtbl_initializer (tree binfo,
7518 int* non_fn_entries_p)
7525 VEC(tree,gc) *vbases;
7527 /* Initialize VID. */
7528 memset (&vid, 0, sizeof (vid));
7531 vid.rtti_binfo = rtti_binfo;
7532 vid.last_init = &vid.inits;
7533 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7534 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7535 vid.generate_vcall_entries = true;
7536 /* The first vbase or vcall offset is at index -3 in the vtable. */
7537 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7539 /* Add entries to the vtable for RTTI. */
7540 build_rtti_vtbl_entries (binfo, &vid);
7542 /* Create an array for keeping track of the functions we've
7543 processed. When we see multiple functions with the same
7544 signature, we share the vcall offsets. */
7545 vid.fns = VEC_alloc (tree, gc, 32);
7546 /* Add the vcall and vbase offset entries. */
7547 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7549 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7550 build_vbase_offset_vtbl_entries. */
7551 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7552 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7553 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7555 /* If the target requires padding between data entries, add that now. */
7556 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7560 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7565 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7566 add = tree_cons (NULL_TREE,
7567 build1 (NOP_EXPR, vtable_entry_type,
7574 if (non_fn_entries_p)
7575 *non_fn_entries_p = list_length (vid.inits);
7577 /* Go through all the ordinary virtual functions, building up
7579 vfun_inits = NULL_TREE;
7580 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7584 tree fn, fn_original;
7585 tree init = NULL_TREE;
7589 if (DECL_THUNK_P (fn))
7591 if (!DECL_NAME (fn))
7593 if (THUNK_ALIAS (fn))
7595 fn = THUNK_ALIAS (fn);
7598 fn_original = THUNK_TARGET (fn);
7601 /* If the only definition of this function signature along our
7602 primary base chain is from a lost primary, this vtable slot will
7603 never be used, so just zero it out. This is important to avoid
7604 requiring extra thunks which cannot be generated with the function.
7606 We first check this in update_vtable_entry_for_fn, so we handle
7607 restored primary bases properly; we also need to do it here so we
7608 zero out unused slots in ctor vtables, rather than filling them
7609 with erroneous values (though harmless, apart from relocation
7611 for (b = binfo; ; b = get_primary_binfo (b))
7613 /* We found a defn before a lost primary; go ahead as normal. */
7614 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7617 /* The nearest definition is from a lost primary; clear the
7619 if (BINFO_LOST_PRIMARY_P (b))
7621 init = size_zero_node;
7628 /* Pull the offset for `this', and the function to call, out of
7630 delta = BV_DELTA (v);
7631 vcall_index = BV_VCALL_INDEX (v);
7633 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7634 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7636 /* You can't call an abstract virtual function; it's abstract.
7637 So, we replace these functions with __pure_virtual. */
7638 if (DECL_PURE_VIRTUAL_P (fn_original))
7641 if (abort_fndecl_addr == NULL)
7642 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7643 init = abort_fndecl_addr;
7647 if (!integer_zerop (delta) || vcall_index)
7649 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7650 if (!DECL_NAME (fn))
7653 /* Take the address of the function, considering it to be of an
7654 appropriate generic type. */
7655 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7659 /* And add it to the chain of initializers. */
7660 if (TARGET_VTABLE_USES_DESCRIPTORS)
7663 if (init == size_zero_node)
7664 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7665 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7667 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7669 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7670 TREE_OPERAND (init, 0),
7671 build_int_cst (NULL_TREE, i));
7672 TREE_CONSTANT (fdesc) = 1;
7674 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7678 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7681 /* The initializers for virtual functions were built up in reverse
7682 order; straighten them out now. */
7683 vfun_inits = nreverse (vfun_inits);
7685 /* The negative offset initializers are also in reverse order. */
7686 vid.inits = nreverse (vid.inits);
7688 /* Chain the two together. */
7689 return chainon (vid.inits, vfun_inits);
7692 /* Adds to vid->inits the initializers for the vbase and vcall
7693 offsets in BINFO, which is in the hierarchy dominated by T. */
7696 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7700 /* If this is a derived class, we must first create entries
7701 corresponding to the primary base class. */
7702 b = get_primary_binfo (binfo);
7704 build_vcall_and_vbase_vtbl_entries (b, vid);
7706 /* Add the vbase entries for this base. */
7707 build_vbase_offset_vtbl_entries (binfo, vid);
7708 /* Add the vcall entries for this base. */
7709 build_vcall_offset_vtbl_entries (binfo, vid);
7712 /* Returns the initializers for the vbase offset entries in the vtable
7713 for BINFO (which is part of the class hierarchy dominated by T), in
7714 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7715 where the next vbase offset will go. */
7718 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7722 tree non_primary_binfo;
7724 /* If there are no virtual baseclasses, then there is nothing to
7726 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7731 /* We might be a primary base class. Go up the inheritance hierarchy
7732 until we find the most derived class of which we are a primary base:
7733 it is the offset of that which we need to use. */
7734 non_primary_binfo = binfo;
7735 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7739 /* If we have reached a virtual base, then it must be a primary
7740 base (possibly multi-level) of vid->binfo, or we wouldn't
7741 have called build_vcall_and_vbase_vtbl_entries for it. But it
7742 might be a lost primary, so just skip down to vid->binfo. */
7743 if (BINFO_VIRTUAL_P (non_primary_binfo))
7745 non_primary_binfo = vid->binfo;
7749 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7750 if (get_primary_binfo (b) != non_primary_binfo)
7752 non_primary_binfo = b;
7755 /* Go through the virtual bases, adding the offsets. */
7756 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7758 vbase = TREE_CHAIN (vbase))
7763 if (!BINFO_VIRTUAL_P (vbase))
7766 /* Find the instance of this virtual base in the complete
7768 b = copied_binfo (vbase, binfo);
7770 /* If we've already got an offset for this virtual base, we
7771 don't need another one. */
7772 if (BINFO_VTABLE_PATH_MARKED (b))
7774 BINFO_VTABLE_PATH_MARKED (b) = 1;
7776 /* Figure out where we can find this vbase offset. */
7777 delta = size_binop (MULT_EXPR,
7780 TYPE_SIZE_UNIT (vtable_entry_type)));
7781 if (vid->primary_vtbl_p)
7782 BINFO_VPTR_FIELD (b) = delta;
7784 if (binfo != TYPE_BINFO (t))
7785 /* The vbase offset had better be the same. */
7786 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7788 /* The next vbase will come at a more negative offset. */
7789 vid->index = size_binop (MINUS_EXPR, vid->index,
7790 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7792 /* The initializer is the delta from BINFO to this virtual base.
7793 The vbase offsets go in reverse inheritance-graph order, and
7794 we are walking in inheritance graph order so these end up in
7796 delta = size_diffop_loc (input_location,
7797 BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7800 = build_tree_list (NULL_TREE,
7801 fold_build1_loc (input_location, NOP_EXPR,
7804 vid->last_init = &TREE_CHAIN (*vid->last_init);
7808 /* Adds the initializers for the vcall offset entries in the vtable
7809 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7813 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7815 /* We only need these entries if this base is a virtual base. We
7816 compute the indices -- but do not add to the vtable -- when
7817 building the main vtable for a class. */
7818 if (binfo == TYPE_BINFO (vid->derived)
7819 || (BINFO_VIRTUAL_P (binfo)
7820 /* If BINFO is RTTI_BINFO, then (since BINFO does not
7821 correspond to VID->DERIVED), we are building a primary
7822 construction virtual table. Since this is a primary
7823 virtual table, we do not need the vcall offsets for
7825 && binfo != vid->rtti_binfo))
7827 /* We need a vcall offset for each of the virtual functions in this
7828 vtable. For example:
7830 class A { virtual void f (); };
7831 class B1 : virtual public A { virtual void f (); };
7832 class B2 : virtual public A { virtual void f (); };
7833 class C: public B1, public B2 { virtual void f (); };
7835 A C object has a primary base of B1, which has a primary base of A. A
7836 C also has a secondary base of B2, which no longer has a primary base
7837 of A. So the B2-in-C construction vtable needs a secondary vtable for
7838 A, which will adjust the A* to a B2* to call f. We have no way of
7839 knowing what (or even whether) this offset will be when we define B2,
7840 so we store this "vcall offset" in the A sub-vtable and look it up in
7841 a "virtual thunk" for B2::f.
7843 We need entries for all the functions in our primary vtable and
7844 in our non-virtual bases' secondary vtables. */
7846 /* If we are just computing the vcall indices -- but do not need
7847 the actual entries -- not that. */
7848 if (!BINFO_VIRTUAL_P (binfo))
7849 vid->generate_vcall_entries = false;
7850 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7851 add_vcall_offset_vtbl_entries_r (binfo, vid);
7855 /* Build vcall offsets, starting with those for BINFO. */
7858 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7864 /* Don't walk into virtual bases -- except, of course, for the
7865 virtual base for which we are building vcall offsets. Any
7866 primary virtual base will have already had its offsets generated
7867 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7868 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7871 /* If BINFO has a primary base, process it first. */
7872 primary_binfo = get_primary_binfo (binfo);
7874 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7876 /* Add BINFO itself to the list. */
7877 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7879 /* Scan the non-primary bases of BINFO. */
7880 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7881 if (base_binfo != primary_binfo)
7882 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7885 /* Called from build_vcall_offset_vtbl_entries_r. */
7888 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7890 /* Make entries for the rest of the virtuals. */
7891 if (abi_version_at_least (2))
7895 /* The ABI requires that the methods be processed in declaration
7896 order. G++ 3.2 used the order in the vtable. */
7897 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7899 orig_fn = TREE_CHAIN (orig_fn))
7900 if (DECL_VINDEX (orig_fn))
7901 add_vcall_offset (orig_fn, binfo, vid);
7905 tree derived_virtuals;
7908 /* If BINFO is a primary base, the most derived class which has
7909 BINFO as a primary base; otherwise, just BINFO. */
7910 tree non_primary_binfo;
7912 /* We might be a primary base class. Go up the inheritance hierarchy
7913 until we find the most derived class of which we are a primary base:
7914 it is the BINFO_VIRTUALS there that we need to consider. */
7915 non_primary_binfo = binfo;
7916 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7920 /* If we have reached a virtual base, then it must be vid->vbase,
7921 because we ignore other virtual bases in
7922 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7923 base (possibly multi-level) of vid->binfo, or we wouldn't
7924 have called build_vcall_and_vbase_vtbl_entries for it. But it
7925 might be a lost primary, so just skip down to vid->binfo. */
7926 if (BINFO_VIRTUAL_P (non_primary_binfo))
7928 gcc_assert (non_primary_binfo == vid->vbase);
7929 non_primary_binfo = vid->binfo;
7933 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7934 if (get_primary_binfo (b) != non_primary_binfo)
7936 non_primary_binfo = b;
7939 if (vid->ctor_vtbl_p)
7940 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7941 where rtti_binfo is the most derived type. */
7943 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7945 for (base_virtuals = BINFO_VIRTUALS (binfo),
7946 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7947 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7949 base_virtuals = TREE_CHAIN (base_virtuals),
7950 derived_virtuals = TREE_CHAIN (derived_virtuals),
7951 orig_virtuals = TREE_CHAIN (orig_virtuals))
7955 /* Find the declaration that originally caused this function to
7956 be present in BINFO_TYPE (binfo). */
7957 orig_fn = BV_FN (orig_virtuals);
7959 /* When processing BINFO, we only want to generate vcall slots for
7960 function slots introduced in BINFO. So don't try to generate
7961 one if the function isn't even defined in BINFO. */
7962 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7965 add_vcall_offset (orig_fn, binfo, vid);
7970 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7973 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7979 /* If there is already an entry for a function with the same
7980 signature as FN, then we do not need a second vcall offset.
7981 Check the list of functions already present in the derived
7983 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7985 if (same_signature_p (derived_entry, orig_fn)
7986 /* We only use one vcall offset for virtual destructors,
7987 even though there are two virtual table entries. */
7988 || (DECL_DESTRUCTOR_P (derived_entry)
7989 && DECL_DESTRUCTOR_P (orig_fn)))
7993 /* If we are building these vcall offsets as part of building
7994 the vtable for the most derived class, remember the vcall
7996 if (vid->binfo == TYPE_BINFO (vid->derived))
7998 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7999 CLASSTYPE_VCALL_INDICES (vid->derived),
8001 elt->purpose = orig_fn;
8002 elt->value = vid->index;
8005 /* The next vcall offset will be found at a more negative
8007 vid->index = size_binop (MINUS_EXPR, vid->index,
8008 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
8010 /* Keep track of this function. */
8011 VEC_safe_push (tree, gc, vid->fns, orig_fn);
8013 if (vid->generate_vcall_entries)
8018 /* Find the overriding function. */
8019 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
8020 if (fn == error_mark_node)
8021 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
8025 base = TREE_VALUE (fn);
8027 /* The vbase we're working on is a primary base of
8028 vid->binfo. But it might be a lost primary, so its
8029 BINFO_OFFSET might be wrong, so we just use the
8030 BINFO_OFFSET from vid->binfo. */
8031 vcall_offset = size_diffop_loc (input_location,
8032 BINFO_OFFSET (base),
8033 BINFO_OFFSET (vid->binfo));
8034 vcall_offset = fold_build1_loc (input_location,
8035 NOP_EXPR, vtable_entry_type,
8038 /* Add the initializer to the vtable. */
8039 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
8040 vid->last_init = &TREE_CHAIN (*vid->last_init);
8044 /* Return vtbl initializers for the RTTI entries corresponding to the
8045 BINFO's vtable. The RTTI entries should indicate the object given
8046 by VID->rtti_binfo. */
8049 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
8058 basetype = BINFO_TYPE (binfo);
8059 t = BINFO_TYPE (vid->rtti_binfo);
8061 /* To find the complete object, we will first convert to our most
8062 primary base, and then add the offset in the vtbl to that value. */
8064 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
8065 && !BINFO_LOST_PRIMARY_P (b))
8069 primary_base = get_primary_binfo (b);
8070 gcc_assert (BINFO_PRIMARY_P (primary_base)
8071 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
8074 offset = size_diffop_loc (input_location,
8075 BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
8077 /* The second entry is the address of the typeinfo object. */
8079 decl = build_address (get_tinfo_decl (t));
8081 decl = integer_zero_node;
8083 /* Convert the declaration to a type that can be stored in the
8085 init = build_nop (vfunc_ptr_type_node, decl);
8086 *vid->last_init = build_tree_list (NULL_TREE, init);
8087 vid->last_init = &TREE_CHAIN (*vid->last_init);
8089 /* Add the offset-to-top entry. It comes earlier in the vtable than
8090 the typeinfo entry. Convert the offset to look like a
8091 function pointer, so that we can put it in the vtable. */
8092 init = build_nop (vfunc_ptr_type_node, offset);
8093 *vid->last_init = build_tree_list (NULL_TREE, init);
8094 vid->last_init = &TREE_CHAIN (*vid->last_init);
8097 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8098 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8101 cp_fold_obj_type_ref (tree ref, tree known_type)
8103 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
8104 HOST_WIDE_INT i = 0;
8105 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
8110 i += (TARGET_VTABLE_USES_DESCRIPTORS
8111 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
8117 #ifdef ENABLE_CHECKING
8118 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
8119 DECL_VINDEX (fndecl)));
8122 cgraph_node (fndecl)->local.vtable_method = true;
8124 return build_address (fndecl);
8127 #include "gt-cp-class.h"