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 fixup_pending_inline (tree);
155 static void fixup_inline_methods (tree);
156 static void propagate_binfo_offsets (tree, tree);
157 static void layout_virtual_bases (record_layout_info, splay_tree);
158 static void build_vbase_offset_vtbl_entries (tree, vtbl_init_data *);
159 static void add_vcall_offset_vtbl_entries_r (tree, vtbl_init_data *);
160 static void add_vcall_offset_vtbl_entries_1 (tree, vtbl_init_data *);
161 static void build_vcall_offset_vtbl_entries (tree, vtbl_init_data *);
162 static void add_vcall_offset (tree, tree, vtbl_init_data *);
163 static void layout_vtable_decl (tree, int);
164 static tree dfs_find_final_overrider_pre (tree, void *);
165 static tree dfs_find_final_overrider_post (tree, void *);
166 static tree find_final_overrider (tree, tree, tree);
167 static int make_new_vtable (tree, tree);
168 static tree get_primary_binfo (tree);
169 static int maybe_indent_hierarchy (FILE *, int, int);
170 static tree dump_class_hierarchy_r (FILE *, int, tree, tree, int);
171 static void dump_class_hierarchy (tree);
172 static void dump_class_hierarchy_1 (FILE *, int, tree);
173 static void dump_array (FILE *, tree);
174 static void dump_vtable (tree, tree, tree);
175 static void dump_vtt (tree, tree);
176 static void dump_thunk (FILE *, int, tree);
177 static tree build_vtable (tree, tree, tree);
178 static void initialize_vtable (tree, tree);
179 static void layout_nonempty_base_or_field (record_layout_info,
180 tree, tree, splay_tree);
181 static tree end_of_class (tree, int);
182 static bool layout_empty_base (record_layout_info, tree, tree, splay_tree);
183 static void accumulate_vtbl_inits (tree, tree, tree, tree, tree);
184 static tree dfs_accumulate_vtbl_inits (tree, tree, tree, tree,
186 static void build_rtti_vtbl_entries (tree, vtbl_init_data *);
187 static void build_vcall_and_vbase_vtbl_entries (tree, vtbl_init_data *);
188 static void clone_constructors_and_destructors (tree);
189 static tree build_clone (tree, tree);
190 static void update_vtable_entry_for_fn (tree, tree, tree, tree *, unsigned);
191 static void build_ctor_vtbl_group (tree, tree);
192 static void build_vtt (tree);
193 static tree binfo_ctor_vtable (tree);
194 static tree *build_vtt_inits (tree, tree, tree *, tree *);
195 static tree dfs_build_secondary_vptr_vtt_inits (tree, void *);
196 static tree dfs_fixup_binfo_vtbls (tree, void *);
197 static int record_subobject_offset (tree, tree, splay_tree);
198 static int check_subobject_offset (tree, tree, splay_tree);
199 static int walk_subobject_offsets (tree, subobject_offset_fn,
200 tree, splay_tree, tree, int);
201 static void record_subobject_offsets (tree, tree, splay_tree, bool);
202 static int layout_conflict_p (tree, tree, splay_tree, int);
203 static int splay_tree_compare_integer_csts (splay_tree_key k1,
205 static void warn_about_ambiguous_bases (tree);
206 static bool type_requires_array_cookie (tree);
207 static bool contains_empty_class_p (tree);
208 static bool base_derived_from (tree, tree);
209 static int empty_base_at_nonzero_offset_p (tree, tree, splay_tree);
210 static tree end_of_base (tree);
211 static tree get_vcall_index (tree, tree);
213 /* Variables shared between class.c and call.c. */
215 #ifdef GATHER_STATISTICS
217 int n_vtable_entries = 0;
218 int n_vtable_searches = 0;
219 int n_vtable_elems = 0;
220 int n_convert_harshness = 0;
221 int n_compute_conversion_costs = 0;
222 int n_inner_fields_searched = 0;
225 /* Convert to or from a base subobject. EXPR is an expression of type
226 `A' or `A*', an expression of type `B' or `B*' is returned. To
227 convert A to a base B, CODE is PLUS_EXPR and BINFO is the binfo for
228 the B base instance within A. To convert base A to derived B, CODE
229 is MINUS_EXPR and BINFO is the binfo for the A instance within B.
230 In this latter case, A must not be a morally virtual base of B.
231 NONNULL is true if EXPR is known to be non-NULL (this is only
232 needed when EXPR is of pointer type). CV qualifiers are preserved
236 build_base_path (enum tree_code code,
241 tree v_binfo = NULL_TREE;
242 tree d_binfo = NULL_TREE;
246 tree null_test = NULL;
247 tree ptr_target_type;
249 int want_pointer = TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE;
250 bool has_empty = false;
253 if (expr == error_mark_node || binfo == error_mark_node || !binfo)
254 return error_mark_node;
256 for (probe = binfo; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
259 if (is_empty_class (BINFO_TYPE (probe)))
261 if (!v_binfo && BINFO_VIRTUAL_P (probe))
265 probe = TYPE_MAIN_VARIANT (TREE_TYPE (expr));
267 probe = TYPE_MAIN_VARIANT (TREE_TYPE (probe));
269 gcc_assert ((code == MINUS_EXPR
270 && SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), probe))
271 || (code == PLUS_EXPR
272 && SAME_BINFO_TYPE_P (BINFO_TYPE (d_binfo), probe)));
274 if (binfo == d_binfo)
278 if (code == MINUS_EXPR && v_binfo)
280 error ("cannot convert from base %qT to derived type %qT via virtual base %qT",
281 BINFO_TYPE (binfo), BINFO_TYPE (d_binfo), BINFO_TYPE (v_binfo));
282 return error_mark_node;
286 /* This must happen before the call to save_expr. */
287 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error);
289 offset = BINFO_OFFSET (binfo);
290 fixed_type_p = resolves_to_fixed_type_p (expr, &nonnull);
291 target_type = code == PLUS_EXPR ? BINFO_TYPE (binfo) : BINFO_TYPE (d_binfo);
293 /* Do we need to look in the vtable for the real offset? */
294 virtual_access = (v_binfo && fixed_type_p <= 0);
296 /* Don't bother with the calculations inside sizeof; they'll ICE if the
297 source type is incomplete and the pointer value doesn't matter. */
300 expr = build_nop (build_pointer_type (target_type), expr);
302 expr = build_indirect_ref (EXPR_LOCATION (expr), expr, NULL);
306 /* Do we need to check for a null pointer? */
307 if (want_pointer && !nonnull)
309 /* If we know the conversion will not actually change the value
310 of EXPR, then we can avoid testing the expression for NULL.
311 We have to avoid generating a COMPONENT_REF for a base class
312 field, because other parts of the compiler know that such
313 expressions are always non-NULL. */
314 if (!virtual_access && integer_zerop (offset))
317 /* TARGET_TYPE has been extracted from BINFO, and, is
318 therefore always cv-unqualified. Extract the
319 cv-qualifiers from EXPR so that the expression returned
320 matches the input. */
321 class_type = TREE_TYPE (TREE_TYPE (expr));
323 = cp_build_qualified_type (target_type,
324 cp_type_quals (class_type));
325 return build_nop (build_pointer_type (target_type), expr);
327 null_test = error_mark_node;
330 /* Protect against multiple evaluation if necessary. */
331 if (TREE_SIDE_EFFECTS (expr) && (null_test || virtual_access))
332 expr = save_expr (expr);
334 /* Now that we've saved expr, build the real null test. */
337 tree zero = cp_convert (TREE_TYPE (expr), integer_zero_node);
338 null_test = fold_build2 (NE_EXPR, boolean_type_node,
342 /* If this is a simple base reference, express it as a COMPONENT_REF. */
343 if (code == PLUS_EXPR && !virtual_access
344 /* We don't build base fields for empty bases, and they aren't very
345 interesting to the optimizers anyway. */
348 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
349 expr = build_simple_base_path (expr, binfo);
351 expr = build_address (expr);
352 target_type = TREE_TYPE (expr);
358 /* Going via virtual base V_BINFO. We need the static offset
359 from V_BINFO to BINFO, and the dynamic offset from D_BINFO to
360 V_BINFO. That offset is an entry in D_BINFO's vtable. */
363 if (fixed_type_p < 0 && in_base_initializer)
365 /* In a base member initializer, we cannot rely on the
366 vtable being set up. We have to indirect via the
370 t = TREE_TYPE (TYPE_VFIELD (current_class_type));
371 t = build_pointer_type (t);
372 v_offset = convert (t, current_vtt_parm);
373 v_offset = cp_build_indirect_ref (v_offset, NULL,
374 tf_warning_or_error);
377 v_offset = build_vfield_ref (cp_build_indirect_ref (expr, NULL,
378 tf_warning_or_error),
379 TREE_TYPE (TREE_TYPE (expr)));
381 v_offset = build2 (POINTER_PLUS_EXPR, TREE_TYPE (v_offset),
382 v_offset, fold_convert (sizetype, BINFO_VPTR_FIELD (v_binfo)));
383 v_offset = build1 (NOP_EXPR,
384 build_pointer_type (ptrdiff_type_node),
386 v_offset = cp_build_indirect_ref (v_offset, NULL, tf_warning_or_error);
387 TREE_CONSTANT (v_offset) = 1;
389 offset = convert_to_integer (ptrdiff_type_node,
391 BINFO_OFFSET (v_binfo)));
393 if (!integer_zerop (offset))
394 v_offset = build2 (code, ptrdiff_type_node, v_offset, offset);
396 if (fixed_type_p < 0)
397 /* Negative fixed_type_p means this is a constructor or destructor;
398 virtual base layout is fixed in in-charge [cd]tors, but not in
400 offset = build3 (COND_EXPR, ptrdiff_type_node,
401 build2 (EQ_EXPR, boolean_type_node,
402 current_in_charge_parm, integer_zero_node),
404 convert_to_integer (ptrdiff_type_node,
405 BINFO_OFFSET (binfo)));
410 target_type = cp_build_qualified_type
411 (target_type, cp_type_quals (TREE_TYPE (TREE_TYPE (expr))));
412 ptr_target_type = build_pointer_type (target_type);
414 target_type = ptr_target_type;
416 expr = build1 (NOP_EXPR, ptr_target_type, expr);
418 if (!integer_zerop (offset))
420 offset = fold_convert (sizetype, offset);
421 if (code == MINUS_EXPR)
422 offset = fold_build1 (NEGATE_EXPR, sizetype, offset);
423 expr = build2 (POINTER_PLUS_EXPR, ptr_target_type, expr, offset);
429 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
433 expr = fold_build3 (COND_EXPR, target_type, null_test, expr,
434 fold_build1 (NOP_EXPR, target_type,
440 /* Subroutine of build_base_path; EXPR and BINFO are as in that function.
441 Perform a derived-to-base conversion by recursively building up a
442 sequence of COMPONENT_REFs to the appropriate base fields. */
445 build_simple_base_path (tree expr, tree binfo)
447 tree type = BINFO_TYPE (binfo);
448 tree d_binfo = BINFO_INHERITANCE_CHAIN (binfo);
451 if (d_binfo == NULL_TREE)
455 gcc_assert (TYPE_MAIN_VARIANT (TREE_TYPE (expr)) == type);
457 /* Transform `(a, b).x' into `(*(a, &b)).x', `(a ? b : c).x'
458 into `(*(a ? &b : &c)).x', and so on. A COND_EXPR is only
459 an lvalue in the front end; only _DECLs and _REFs are lvalues
461 temp = unary_complex_lvalue (ADDR_EXPR, expr);
463 expr = cp_build_indirect_ref (temp, NULL, tf_warning_or_error);
469 expr = build_simple_base_path (expr, d_binfo);
471 for (field = TYPE_FIELDS (BINFO_TYPE (d_binfo));
472 field; field = TREE_CHAIN (field))
473 /* Is this the base field created by build_base_field? */
474 if (TREE_CODE (field) == FIELD_DECL
475 && DECL_FIELD_IS_BASE (field)
476 && TREE_TYPE (field) == type)
478 /* We don't use build_class_member_access_expr here, as that
479 has unnecessary checks, and more importantly results in
480 recursive calls to dfs_walk_once. */
481 int type_quals = cp_type_quals (TREE_TYPE (expr));
483 expr = build3 (COMPONENT_REF,
484 cp_build_qualified_type (type, type_quals),
485 expr, field, NULL_TREE);
486 expr = fold_if_not_in_template (expr);
488 /* Mark the expression const or volatile, as appropriate.
489 Even though we've dealt with the type above, we still have
490 to mark the expression itself. */
491 if (type_quals & TYPE_QUAL_CONST)
492 TREE_READONLY (expr) = 1;
493 if (type_quals & TYPE_QUAL_VOLATILE)
494 TREE_THIS_VOLATILE (expr) = 1;
499 /* Didn't find the base field?!? */
503 /* Convert OBJECT to the base TYPE. OBJECT is an expression whose
504 type is a class type or a pointer to a class type. In the former
505 case, TYPE is also a class type; in the latter it is another
506 pointer type. If CHECK_ACCESS is true, an error message is emitted
507 if TYPE is inaccessible. If OBJECT has pointer type, the value is
508 assumed to be non-NULL. */
511 convert_to_base (tree object, tree type, bool check_access, bool nonnull)
516 if (TYPE_PTR_P (TREE_TYPE (object)))
518 object_type = TREE_TYPE (TREE_TYPE (object));
519 type = TREE_TYPE (type);
522 object_type = TREE_TYPE (object);
524 binfo = lookup_base (object_type, type,
525 check_access ? ba_check : ba_unique,
527 if (!binfo || binfo == error_mark_node)
528 return error_mark_node;
530 return build_base_path (PLUS_EXPR, object, binfo, nonnull);
533 /* EXPR is an expression with unqualified class type. BASE is a base
534 binfo of that class type. Returns EXPR, converted to the BASE
535 type. This function assumes that EXPR is the most derived class;
536 therefore virtual bases can be found at their static offsets. */
539 convert_to_base_statically (tree expr, tree base)
543 expr_type = TREE_TYPE (expr);
544 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (base), expr_type))
548 pointer_type = build_pointer_type (expr_type);
550 /* We use fold_build2 and fold_convert below to simplify the trees
551 provided to the optimizers. It is not safe to call these functions
552 when processing a template because they do not handle C++-specific
554 gcc_assert (!processing_template_decl);
555 expr = cp_build_unary_op (ADDR_EXPR, expr, /*noconvert=*/1,
556 tf_warning_or_error);
557 if (!integer_zerop (BINFO_OFFSET (base)))
558 expr = fold_build2 (POINTER_PLUS_EXPR, pointer_type, expr,
559 fold_convert (sizetype, BINFO_OFFSET (base)));
560 expr = fold_convert (build_pointer_type (BINFO_TYPE (base)), expr);
561 expr = build_fold_indirect_ref (expr);
569 build_vfield_ref (tree datum, tree type)
571 tree vfield, vcontext;
573 if (datum == error_mark_node)
574 return error_mark_node;
576 /* First, convert to the requested type. */
577 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (datum), type))
578 datum = convert_to_base (datum, type, /*check_access=*/false,
581 /* Second, the requested type may not be the owner of its own vptr.
582 If not, convert to the base class that owns it. We cannot use
583 convert_to_base here, because VCONTEXT may appear more than once
584 in the inheritance hierarchy of TYPE, and thus direct conversion
585 between the types may be ambiguous. Following the path back up
586 one step at a time via primary bases avoids the problem. */
587 vfield = TYPE_VFIELD (type);
588 vcontext = DECL_CONTEXT (vfield);
589 while (!same_type_ignoring_top_level_qualifiers_p (vcontext, type))
591 datum = build_simple_base_path (datum, CLASSTYPE_PRIMARY_BINFO (type));
592 type = TREE_TYPE (datum);
595 return build3 (COMPONENT_REF, TREE_TYPE (vfield), datum, vfield, NULL_TREE);
598 /* Given an object INSTANCE, return an expression which yields the
599 vtable element corresponding to INDEX. There are many special
600 cases for INSTANCE which we take care of here, mainly to avoid
601 creating extra tree nodes when we don't have to. */
604 build_vtbl_ref_1 (tree instance, tree idx)
607 tree vtbl = NULL_TREE;
609 /* Try to figure out what a reference refers to, and
610 access its virtual function table directly. */
613 tree fixed_type = fixed_type_or_null (instance, NULL, &cdtorp);
615 tree basetype = non_reference (TREE_TYPE (instance));
617 if (fixed_type && !cdtorp)
619 tree binfo = lookup_base (fixed_type, basetype,
620 ba_unique | ba_quiet, NULL);
622 vtbl = unshare_expr (BINFO_VTABLE (binfo));
626 vtbl = build_vfield_ref (instance, basetype);
629 aref = build_array_ref (vtbl, idx, input_location);
630 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
636 build_vtbl_ref (tree instance, tree idx)
638 tree aref = build_vtbl_ref_1 (instance, idx);
643 /* Given a stable object pointer INSTANCE_PTR, return an expression which
644 yields a function pointer corresponding to vtable element INDEX. */
647 build_vfn_ref (tree instance_ptr, tree idx)
651 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, 0,
652 tf_warning_or_error),
655 /* When using function descriptors, the address of the
656 vtable entry is treated as a function pointer. */
657 if (TARGET_VTABLE_USES_DESCRIPTORS)
658 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
659 cp_build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1,
660 tf_warning_or_error));
662 /* Remember this as a method reference, for later devirtualization. */
663 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
668 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
669 for the given TYPE. */
672 get_vtable_name (tree type)
674 return mangle_vtbl_for_type (type);
677 /* DECL is an entity associated with TYPE, like a virtual table or an
678 implicitly generated constructor. Determine whether or not DECL
679 should have external or internal linkage at the object file
680 level. This routine does not deal with COMDAT linkage and other
681 similar complexities; it simply sets TREE_PUBLIC if it possible for
682 entities in other translation units to contain copies of DECL, in
686 set_linkage_according_to_type (tree type, tree decl)
688 /* If TYPE involves a local class in a function with internal
689 linkage, then DECL should have internal linkage too. Other local
690 classes have no linkage -- but if their containing functions
691 have external linkage, it makes sense for DECL to have external
692 linkage too. That will allow template definitions to be merged,
694 if (no_linkage_check (type, /*relaxed_p=*/true))
696 TREE_PUBLIC (decl) = 0;
697 DECL_INTERFACE_KNOWN (decl) = 1;
700 TREE_PUBLIC (decl) = 1;
703 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
704 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
705 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
708 build_vtable (tree class_type, tree name, tree vtable_type)
712 decl = build_lang_decl (VAR_DECL, name, vtable_type);
713 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
714 now to avoid confusion in mangle_decl. */
715 SET_DECL_ASSEMBLER_NAME (decl, name);
716 DECL_CONTEXT (decl) = class_type;
717 DECL_ARTIFICIAL (decl) = 1;
718 TREE_STATIC (decl) = 1;
719 TREE_READONLY (decl) = 1;
720 DECL_VIRTUAL_P (decl) = 1;
721 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
722 DECL_VTABLE_OR_VTT_P (decl) = 1;
723 /* At one time the vtable info was grabbed 2 words at a time. This
724 fails on sparc unless you have 8-byte alignment. (tiemann) */
725 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
727 set_linkage_according_to_type (class_type, decl);
728 /* The vtable has not been defined -- yet. */
729 DECL_EXTERNAL (decl) = 1;
730 DECL_NOT_REALLY_EXTERN (decl) = 1;
732 /* Mark the VAR_DECL node representing the vtable itself as a
733 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
734 is rather important that such things be ignored because any
735 effort to actually generate DWARF for them will run into
736 trouble when/if we encounter code like:
739 struct S { virtual void member (); };
741 because the artificial declaration of the vtable itself (as
742 manufactured by the g++ front end) will say that the vtable is
743 a static member of `S' but only *after* the debug output for
744 the definition of `S' has already been output. This causes
745 grief because the DWARF entry for the definition of the vtable
746 will try to refer back to an earlier *declaration* of the
747 vtable as a static member of `S' and there won't be one. We
748 might be able to arrange to have the "vtable static member"
749 attached to the member list for `S' before the debug info for
750 `S' get written (which would solve the problem) but that would
751 require more intrusive changes to the g++ front end. */
752 DECL_IGNORED_P (decl) = 1;
757 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
758 or even complete. If this does not exist, create it. If COMPLETE is
759 nonzero, then complete the definition of it -- that will render it
760 impossible to actually build the vtable, but is useful to get at those
761 which are known to exist in the runtime. */
764 get_vtable_decl (tree type, int complete)
768 if (CLASSTYPE_VTABLES (type))
769 return CLASSTYPE_VTABLES (type);
771 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
772 CLASSTYPE_VTABLES (type) = decl;
776 DECL_EXTERNAL (decl) = 1;
777 finish_decl (decl, NULL_TREE, NULL_TREE, NULL_TREE);
783 /* Build the primary virtual function table for TYPE. If BINFO is
784 non-NULL, build the vtable starting with the initial approximation
785 that it is the same as the one which is the head of the association
786 list. Returns a nonzero value if a new vtable is actually
790 build_primary_vtable (tree binfo, tree type)
795 decl = get_vtable_decl (type, /*complete=*/0);
799 if (BINFO_NEW_VTABLE_MARKED (binfo))
800 /* We have already created a vtable for this base, so there's
801 no need to do it again. */
804 virtuals = copy_list (BINFO_VIRTUALS (binfo));
805 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
806 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
807 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
811 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
812 virtuals = NULL_TREE;
815 #ifdef GATHER_STATISTICS
817 n_vtable_elems += list_length (virtuals);
820 /* Initialize the association list for this type, based
821 on our first approximation. */
822 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
823 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
824 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
828 /* Give BINFO a new virtual function table which is initialized
829 with a skeleton-copy of its original initialization. The only
830 entry that changes is the `delta' entry, so we can really
831 share a lot of structure.
833 FOR_TYPE is the most derived type which caused this table to
836 Returns nonzero if we haven't met BINFO before.
838 The order in which vtables are built (by calling this function) for
839 an object must remain the same, otherwise a binary incompatibility
843 build_secondary_vtable (tree binfo)
845 if (BINFO_NEW_VTABLE_MARKED (binfo))
846 /* We already created a vtable for this base. There's no need to
850 /* Remember that we've created a vtable for this BINFO, so that we
851 don't try to do so again. */
852 SET_BINFO_NEW_VTABLE_MARKED (binfo);
854 /* Make fresh virtual list, so we can smash it later. */
855 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
857 /* Secondary vtables are laid out as part of the same structure as
858 the primary vtable. */
859 BINFO_VTABLE (binfo) = NULL_TREE;
863 /* Create a new vtable for BINFO which is the hierarchy dominated by
864 T. Return nonzero if we actually created a new vtable. */
867 make_new_vtable (tree t, tree binfo)
869 if (binfo == TYPE_BINFO (t))
870 /* In this case, it is *type*'s vtable we are modifying. We start
871 with the approximation that its vtable is that of the
872 immediate base class. */
873 return build_primary_vtable (binfo, t);
875 /* This is our very own copy of `basetype' to play with. Later,
876 we will fill in all the virtual functions that override the
877 virtual functions in these base classes which are not defined
878 by the current type. */
879 return build_secondary_vtable (binfo);
882 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
883 (which is in the hierarchy dominated by T) list FNDECL as its
884 BV_FN. DELTA is the required constant adjustment from the `this'
885 pointer where the vtable entry appears to the `this' required when
886 the function is actually called. */
889 modify_vtable_entry (tree t,
899 if (fndecl != BV_FN (v)
900 || !tree_int_cst_equal (delta, BV_DELTA (v)))
902 /* We need a new vtable for BINFO. */
903 if (make_new_vtable (t, binfo))
905 /* If we really did make a new vtable, we also made a copy
906 of the BINFO_VIRTUALS list. Now, we have to find the
907 corresponding entry in that list. */
908 *virtuals = BINFO_VIRTUALS (binfo);
909 while (BV_FN (*virtuals) != BV_FN (v))
910 *virtuals = TREE_CHAIN (*virtuals);
914 BV_DELTA (v) = delta;
915 BV_VCALL_INDEX (v) = NULL_TREE;
921 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
922 the USING_DECL naming METHOD. Returns true if the method could be
923 added to the method vec. */
926 add_method (tree type, tree method, tree using_decl)
930 bool template_conv_p = false;
932 VEC(tree,gc) *method_vec;
934 bool insert_p = false;
938 if (method == error_mark_node)
941 complete_p = COMPLETE_TYPE_P (type);
942 conv_p = DECL_CONV_FN_P (method);
944 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
945 && DECL_TEMPLATE_CONV_FN_P (method));
947 method_vec = CLASSTYPE_METHOD_VEC (type);
950 /* Make a new method vector. We start with 8 entries. We must
951 allocate at least two (for constructors and destructors), and
952 we're going to end up with an assignment operator at some
954 method_vec = VEC_alloc (tree, gc, 8);
955 /* Create slots for constructors and destructors. */
956 VEC_quick_push (tree, method_vec, NULL_TREE);
957 VEC_quick_push (tree, method_vec, NULL_TREE);
958 CLASSTYPE_METHOD_VEC (type) = method_vec;
961 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
962 grok_special_member_properties (method);
964 /* Constructors and destructors go in special slots. */
965 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
966 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
967 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
969 slot = CLASSTYPE_DESTRUCTOR_SLOT;
971 if (TYPE_FOR_JAVA (type))
973 if (!DECL_ARTIFICIAL (method))
974 error ("Java class %qT cannot have a destructor", type);
975 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
976 error ("Java class %qT cannot have an implicit non-trivial "
986 /* See if we already have an entry with this name. */
987 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
988 VEC_iterate (tree, method_vec, slot, m);
994 if (TREE_CODE (m) == TEMPLATE_DECL
995 && DECL_TEMPLATE_CONV_FN_P (m))
999 if (conv_p && !DECL_CONV_FN_P (m))
1001 if (DECL_NAME (m) == DECL_NAME (method))
1007 && !DECL_CONV_FN_P (m)
1008 && DECL_NAME (m) > DECL_NAME (method))
1012 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
1014 /* Check to see if we've already got this method. */
1015 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
1017 tree fn = OVL_CURRENT (fns);
1023 if (TREE_CODE (fn) != TREE_CODE (method))
1026 /* [over.load] Member function declarations with the
1027 same name and the same parameter types cannot be
1028 overloaded if any of them is a static member
1029 function declaration.
1031 [namespace.udecl] When a using-declaration brings names
1032 from a base class into a derived class scope, member
1033 functions in the derived class override and/or hide member
1034 functions with the same name and parameter types in a base
1035 class (rather than conflicting). */
1036 fn_type = TREE_TYPE (fn);
1037 method_type = TREE_TYPE (method);
1038 parms1 = TYPE_ARG_TYPES (fn_type);
1039 parms2 = TYPE_ARG_TYPES (method_type);
1041 /* Compare the quals on the 'this' parm. Don't compare
1042 the whole types, as used functions are treated as
1043 coming from the using class in overload resolution. */
1044 if (! DECL_STATIC_FUNCTION_P (fn)
1045 && ! DECL_STATIC_FUNCTION_P (method)
1046 && TREE_TYPE (TREE_VALUE (parms1)) != error_mark_node
1047 && TREE_TYPE (TREE_VALUE (parms2)) != error_mark_node
1048 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1049 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1052 /* For templates, the return type and template parameters
1053 must be identical. */
1054 if (TREE_CODE (fn) == TEMPLATE_DECL
1055 && (!same_type_p (TREE_TYPE (fn_type),
1056 TREE_TYPE (method_type))
1057 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1058 DECL_TEMPLATE_PARMS (method))))
1061 if (! DECL_STATIC_FUNCTION_P (fn))
1062 parms1 = TREE_CHAIN (parms1);
1063 if (! DECL_STATIC_FUNCTION_P (method))
1064 parms2 = TREE_CHAIN (parms2);
1066 if (compparms (parms1, parms2)
1067 && (!DECL_CONV_FN_P (fn)
1068 || same_type_p (TREE_TYPE (fn_type),
1069 TREE_TYPE (method_type))))
1073 if (DECL_CONTEXT (fn) == type)
1074 /* Defer to the local function. */
1076 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1077 error ("repeated using declaration %q+D", using_decl);
1079 error ("using declaration %q+D conflicts with a previous using declaration",
1084 error ("%q+#D cannot be overloaded", method);
1085 error ("with %q+#D", fn);
1088 /* We don't call duplicate_decls here to merge the
1089 declarations because that will confuse things if the
1090 methods have inline definitions. In particular, we
1091 will crash while processing the definitions. */
1096 /* A class should never have more than one destructor. */
1097 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1100 /* Add the new binding. */
1101 overload = build_overload (method, current_fns);
1104 TYPE_HAS_CONVERSION (type) = 1;
1105 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1106 push_class_level_binding (DECL_NAME (method), overload);
1112 /* We only expect to add few methods in the COMPLETE_P case, so
1113 just make room for one more method in that case. */
1115 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1);
1117 reallocated = VEC_reserve (tree, gc, method_vec, 1);
1119 CLASSTYPE_METHOD_VEC (type) = method_vec;
1120 if (slot == VEC_length (tree, method_vec))
1121 VEC_quick_push (tree, method_vec, overload);
1123 VEC_quick_insert (tree, method_vec, slot, overload);
1126 /* Replace the current slot. */
1127 VEC_replace (tree, method_vec, slot, overload);
1131 /* Subroutines of finish_struct. */
1133 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1134 legit, otherwise return 0. */
1137 alter_access (tree t, tree fdecl, tree access)
1141 if (!DECL_LANG_SPECIFIC (fdecl))
1142 retrofit_lang_decl (fdecl);
1144 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1146 elem = purpose_member (t, DECL_ACCESS (fdecl));
1149 if (TREE_VALUE (elem) != access)
1151 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1152 error ("conflicting access specifications for method"
1153 " %q+D, ignored", TREE_TYPE (fdecl));
1155 error ("conflicting access specifications for field %qE, ignored",
1160 /* They're changing the access to the same thing they changed
1161 it to before. That's OK. */
1167 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl);
1168 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1174 /* Process the USING_DECL, which is a member of T. */
1177 handle_using_decl (tree using_decl, tree t)
1179 tree decl = USING_DECL_DECLS (using_decl);
1180 tree name = DECL_NAME (using_decl);
1182 = TREE_PRIVATE (using_decl) ? access_private_node
1183 : TREE_PROTECTED (using_decl) ? access_protected_node
1184 : access_public_node;
1185 tree flist = NULL_TREE;
1188 gcc_assert (!processing_template_decl && decl);
1190 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1193 if (is_overloaded_fn (old_value))
1194 old_value = OVL_CURRENT (old_value);
1196 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1199 old_value = NULL_TREE;
1202 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1204 if (is_overloaded_fn (decl))
1209 else if (is_overloaded_fn (old_value))
1212 /* It's OK to use functions from a base when there are functions with
1213 the same name already present in the current class. */;
1216 error ("%q+D invalid in %q#T", using_decl, t);
1217 error (" because of local method %q+#D with same name",
1218 OVL_CURRENT (old_value));
1222 else if (!DECL_ARTIFICIAL (old_value))
1224 error ("%q+D invalid in %q#T", using_decl, t);
1225 error (" because of local member %q+#D with same name", old_value);
1229 /* Make type T see field decl FDECL with access ACCESS. */
1231 for (; flist; flist = OVL_NEXT (flist))
1233 add_method (t, OVL_CURRENT (flist), using_decl);
1234 alter_access (t, OVL_CURRENT (flist), access);
1237 alter_access (t, decl, access);
1240 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1241 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1242 properties of the bases. */
1245 check_bases (tree t,
1246 int* cant_have_const_ctor_p,
1247 int* no_const_asn_ref_p)
1250 int seen_non_virtual_nearly_empty_base_p;
1254 seen_non_virtual_nearly_empty_base_p = 0;
1256 for (binfo = TYPE_BINFO (t), i = 0;
1257 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1259 tree basetype = TREE_TYPE (base_binfo);
1261 gcc_assert (COMPLETE_TYPE_P (basetype));
1263 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1264 here because the case of virtual functions but non-virtual
1265 dtor is handled in finish_struct_1. */
1266 if (!TYPE_POLYMORPHIC_P (basetype))
1267 warning (OPT_Weffc__,
1268 "base class %q#T has a non-virtual destructor", basetype);
1270 /* If the base class doesn't have copy constructors or
1271 assignment operators that take const references, then the
1272 derived class cannot have such a member automatically
1274 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1275 *cant_have_const_ctor_p = 1;
1276 if (TYPE_HAS_ASSIGN_REF (basetype)
1277 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1278 *no_const_asn_ref_p = 1;
1280 if (BINFO_VIRTUAL_P (base_binfo))
1281 /* A virtual base does not effect nearly emptiness. */
1283 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1285 if (seen_non_virtual_nearly_empty_base_p)
1286 /* And if there is more than one nearly empty base, then the
1287 derived class is not nearly empty either. */
1288 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1290 /* Remember we've seen one. */
1291 seen_non_virtual_nearly_empty_base_p = 1;
1293 else if (!is_empty_class (basetype))
1294 /* If the base class is not empty or nearly empty, then this
1295 class cannot be nearly empty. */
1296 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1298 /* A lot of properties from the bases also apply to the derived
1300 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1301 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1302 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1303 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1304 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1305 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1306 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1307 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1308 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1309 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (basetype);
1313 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1314 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1315 that have had a nearly-empty virtual primary base stolen by some
1316 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1320 determine_primary_bases (tree t)
1323 tree primary = NULL_TREE;
1324 tree type_binfo = TYPE_BINFO (t);
1327 /* Determine the primary bases of our bases. */
1328 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1329 base_binfo = TREE_CHAIN (base_binfo))
1331 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1333 /* See if we're the non-virtual primary of our inheritance
1335 if (!BINFO_VIRTUAL_P (base_binfo))
1337 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1338 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1341 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1342 BINFO_TYPE (parent_primary)))
1343 /* We are the primary binfo. */
1344 BINFO_PRIMARY_P (base_binfo) = 1;
1346 /* Determine if we have a virtual primary base, and mark it so.
1348 if (primary && BINFO_VIRTUAL_P (primary))
1350 tree this_primary = copied_binfo (primary, base_binfo);
1352 if (BINFO_PRIMARY_P (this_primary))
1353 /* Someone already claimed this base. */
1354 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1359 BINFO_PRIMARY_P (this_primary) = 1;
1360 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1362 /* A virtual binfo might have been copied from within
1363 another hierarchy. As we're about to use it as a
1364 primary base, make sure the offsets match. */
1365 delta = size_diffop (convert (ssizetype,
1366 BINFO_OFFSET (base_binfo)),
1368 BINFO_OFFSET (this_primary)));
1370 propagate_binfo_offsets (this_primary, delta);
1375 /* First look for a dynamic direct non-virtual base. */
1376 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1378 tree basetype = BINFO_TYPE (base_binfo);
1380 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1382 primary = base_binfo;
1387 /* A "nearly-empty" virtual base class can be the primary base
1388 class, if no non-virtual polymorphic base can be found. Look for
1389 a nearly-empty virtual dynamic base that is not already a primary
1390 base of something in the hierarchy. If there is no such base,
1391 just pick the first nearly-empty virtual base. */
1393 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1394 base_binfo = TREE_CHAIN (base_binfo))
1395 if (BINFO_VIRTUAL_P (base_binfo)
1396 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1398 if (!BINFO_PRIMARY_P (base_binfo))
1400 /* Found one that is not primary. */
1401 primary = base_binfo;
1405 /* Remember the first candidate. */
1406 primary = base_binfo;
1410 /* If we've got a primary base, use it. */
1413 tree basetype = BINFO_TYPE (primary);
1415 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1416 if (BINFO_PRIMARY_P (primary))
1417 /* We are stealing a primary base. */
1418 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1419 BINFO_PRIMARY_P (primary) = 1;
1420 if (BINFO_VIRTUAL_P (primary))
1424 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1425 /* A virtual binfo might have been copied from within
1426 another hierarchy. As we're about to use it as a primary
1427 base, make sure the offsets match. */
1428 delta = size_diffop (ssize_int (0),
1429 convert (ssizetype, BINFO_OFFSET (primary)));
1431 propagate_binfo_offsets (primary, delta);
1434 primary = TYPE_BINFO (basetype);
1436 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1437 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1438 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1442 /* Update the variant types of T. */
1445 fixup_type_variants (tree t)
1452 for (variants = TYPE_NEXT_VARIANT (t);
1454 variants = TYPE_NEXT_VARIANT (variants))
1456 /* These fields are in the _TYPE part of the node, not in
1457 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1458 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
1459 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1460 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1461 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1463 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1465 TYPE_BINFO (variants) = TYPE_BINFO (t);
1467 /* Copy whatever these are holding today. */
1468 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1469 TYPE_METHODS (variants) = TYPE_METHODS (t);
1470 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1472 /* All variants of a class have the same attributes. */
1473 TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t);
1478 /* Set memoizing fields and bits of T (and its variants) for later
1482 finish_struct_bits (tree t)
1484 /* Fix up variants (if any). */
1485 fixup_type_variants (t);
1487 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1488 /* For a class w/o baseclasses, 'finish_struct' has set
1489 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1490 Similarly for a class whose base classes do not have vtables.
1491 When neither of these is true, we might have removed abstract
1492 virtuals (by providing a definition), added some (by declaring
1493 new ones), or redeclared ones from a base class. We need to
1494 recalculate what's really an abstract virtual at this point (by
1495 looking in the vtables). */
1496 get_pure_virtuals (t);
1498 /* If this type has a copy constructor or a destructor, force its
1499 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1500 nonzero. This will cause it to be passed by invisible reference
1501 and prevent it from being returned in a register. */
1502 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1505 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1506 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1508 SET_TYPE_MODE (variants, BLKmode);
1509 TREE_ADDRESSABLE (variants) = 1;
1514 /* Issue warnings about T having private constructors, but no friends,
1517 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1518 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1519 non-private static member functions. */
1522 maybe_warn_about_overly_private_class (tree t)
1524 int has_member_fn = 0;
1525 int has_nonprivate_method = 0;
1528 if (!warn_ctor_dtor_privacy
1529 /* If the class has friends, those entities might create and
1530 access instances, so we should not warn. */
1531 || (CLASSTYPE_FRIEND_CLASSES (t)
1532 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1533 /* We will have warned when the template was declared; there's
1534 no need to warn on every instantiation. */
1535 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1536 /* There's no reason to even consider warning about this
1540 /* We only issue one warning, if more than one applies, because
1541 otherwise, on code like:
1544 // Oops - forgot `public:'
1550 we warn several times about essentially the same problem. */
1552 /* Check to see if all (non-constructor, non-destructor) member
1553 functions are private. (Since there are no friends or
1554 non-private statics, we can't ever call any of the private member
1556 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1557 /* We're not interested in compiler-generated methods; they don't
1558 provide any way to call private members. */
1559 if (!DECL_ARTIFICIAL (fn))
1561 if (!TREE_PRIVATE (fn))
1563 if (DECL_STATIC_FUNCTION_P (fn))
1564 /* A non-private static member function is just like a
1565 friend; it can create and invoke private member
1566 functions, and be accessed without a class
1570 has_nonprivate_method = 1;
1571 /* Keep searching for a static member function. */
1573 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1577 if (!has_nonprivate_method && has_member_fn)
1579 /* There are no non-private methods, and there's at least one
1580 private member function that isn't a constructor or
1581 destructor. (If all the private members are
1582 constructors/destructors we want to use the code below that
1583 issues error messages specifically referring to
1584 constructors/destructors.) */
1586 tree binfo = TYPE_BINFO (t);
1588 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1589 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1591 has_nonprivate_method = 1;
1594 if (!has_nonprivate_method)
1596 warning (OPT_Wctor_dtor_privacy,
1597 "all member functions in class %qT are private", t);
1602 /* Even if some of the member functions are non-private, the class
1603 won't be useful for much if all the constructors or destructors
1604 are private: such an object can never be created or destroyed. */
1605 fn = CLASSTYPE_DESTRUCTORS (t);
1606 if (fn && TREE_PRIVATE (fn))
1608 warning (OPT_Wctor_dtor_privacy,
1609 "%q#T only defines a private destructor and has no friends",
1614 /* Warn about classes that have private constructors and no friends. */
1615 if (TYPE_HAS_USER_CONSTRUCTOR (t)
1616 /* Implicitly generated constructors are always public. */
1617 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1618 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1620 int nonprivate_ctor = 0;
1622 /* If a non-template class does not define a copy
1623 constructor, one is defined for it, enabling it to avoid
1624 this warning. For a template class, this does not
1625 happen, and so we would normally get a warning on:
1627 template <class T> class C { private: C(); };
1629 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1630 complete non-template or fully instantiated classes have this
1632 if (!TYPE_HAS_INIT_REF (t))
1633 nonprivate_ctor = 1;
1635 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1637 tree ctor = OVL_CURRENT (fn);
1638 /* Ideally, we wouldn't count copy constructors (or, in
1639 fact, any constructor that takes an argument of the
1640 class type as a parameter) because such things cannot
1641 be used to construct an instance of the class unless
1642 you already have one. But, for now at least, we're
1644 if (! TREE_PRIVATE (ctor))
1646 nonprivate_ctor = 1;
1651 if (nonprivate_ctor == 0)
1653 warning (OPT_Wctor_dtor_privacy,
1654 "%q#T only defines private constructors and has no friends",
1662 gt_pointer_operator new_value;
1666 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1669 method_name_cmp (const void* m1_p, const void* m2_p)
1671 const tree *const m1 = (const tree *) m1_p;
1672 const tree *const m2 = (const tree *) m2_p;
1674 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1676 if (*m1 == NULL_TREE)
1678 if (*m2 == NULL_TREE)
1680 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1685 /* This routine compares two fields like method_name_cmp but using the
1686 pointer operator in resort_field_decl_data. */
1689 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1691 const tree *const m1 = (const tree *) m1_p;
1692 const tree *const m2 = (const tree *) m2_p;
1693 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1695 if (*m1 == NULL_TREE)
1697 if (*m2 == NULL_TREE)
1700 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1701 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1702 resort_data.new_value (&d1, resort_data.cookie);
1703 resort_data.new_value (&d2, resort_data.cookie);
1710 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1713 resort_type_method_vec (void* obj,
1714 void* orig_obj ATTRIBUTE_UNUSED ,
1715 gt_pointer_operator new_value,
1718 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1719 int len = VEC_length (tree, method_vec);
1723 /* The type conversion ops have to live at the front of the vec, so we
1725 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1726 VEC_iterate (tree, method_vec, slot, fn);
1728 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1733 resort_data.new_value = new_value;
1734 resort_data.cookie = cookie;
1735 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1736 resort_method_name_cmp);
1740 /* Warn about duplicate methods in fn_fields.
1742 Sort methods that are not special (i.e., constructors, destructors,
1743 and type conversion operators) so that we can find them faster in
1747 finish_struct_methods (tree t)
1750 VEC(tree,gc) *method_vec;
1753 method_vec = CLASSTYPE_METHOD_VEC (t);
1757 len = VEC_length (tree, method_vec);
1759 /* Clear DECL_IN_AGGR_P for all functions. */
1760 for (fn_fields = TYPE_METHODS (t); fn_fields;
1761 fn_fields = TREE_CHAIN (fn_fields))
1762 DECL_IN_AGGR_P (fn_fields) = 0;
1764 /* Issue warnings about private constructors and such. If there are
1765 no methods, then some public defaults are generated. */
1766 maybe_warn_about_overly_private_class (t);
1768 /* The type conversion ops have to live at the front of the vec, so we
1770 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1771 VEC_iterate (tree, method_vec, slot, fn_fields);
1773 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1776 qsort (VEC_address (tree, method_vec) + slot,
1777 len-slot, sizeof (tree), method_name_cmp);
1780 /* Make BINFO's vtable have N entries, including RTTI entries,
1781 vbase and vcall offsets, etc. Set its type and call the back end
1785 layout_vtable_decl (tree binfo, int n)
1790 atype = build_cplus_array_type (vtable_entry_type,
1791 build_index_type (size_int (n - 1)));
1792 layout_type (atype);
1794 /* We may have to grow the vtable. */
1795 vtable = get_vtbl_decl_for_binfo (binfo);
1796 if (!same_type_p (TREE_TYPE (vtable), atype))
1798 TREE_TYPE (vtable) = atype;
1799 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1800 layout_decl (vtable, 0);
1804 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1805 have the same signature. */
1808 same_signature_p (const_tree fndecl, const_tree base_fndecl)
1810 /* One destructor overrides another if they are the same kind of
1812 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1813 && special_function_p (base_fndecl) == special_function_p (fndecl))
1815 /* But a non-destructor never overrides a destructor, nor vice
1816 versa, nor do different kinds of destructors override
1817 one-another. For example, a complete object destructor does not
1818 override a deleting destructor. */
1819 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1822 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1823 || (DECL_CONV_FN_P (fndecl)
1824 && DECL_CONV_FN_P (base_fndecl)
1825 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1826 DECL_CONV_FN_TYPE (base_fndecl))))
1828 tree types, base_types;
1829 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1830 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1831 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1832 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1833 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1839 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1843 base_derived_from (tree derived, tree base)
1847 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1849 if (probe == derived)
1851 else if (BINFO_VIRTUAL_P (probe))
1852 /* If we meet a virtual base, we can't follow the inheritance
1853 any more. See if the complete type of DERIVED contains
1854 such a virtual base. */
1855 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1861 typedef struct find_final_overrider_data_s {
1862 /* The function for which we are trying to find a final overrider. */
1864 /* The base class in which the function was declared. */
1865 tree declaring_base;
1866 /* The candidate overriders. */
1868 /* Path to most derived. */
1869 VEC(tree,heap) *path;
1870 } find_final_overrider_data;
1872 /* Add the overrider along the current path to FFOD->CANDIDATES.
1873 Returns true if an overrider was found; false otherwise. */
1876 dfs_find_final_overrider_1 (tree binfo,
1877 find_final_overrider_data *ffod,
1882 /* If BINFO is not the most derived type, try a more derived class.
1883 A definition there will overrider a definition here. */
1887 if (dfs_find_final_overrider_1
1888 (VEC_index (tree, ffod->path, depth), ffod, depth))
1892 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1895 tree *candidate = &ffod->candidates;
1897 /* Remove any candidates overridden by this new function. */
1900 /* If *CANDIDATE overrides METHOD, then METHOD
1901 cannot override anything else on the list. */
1902 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1904 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1905 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1906 *candidate = TREE_CHAIN (*candidate);
1908 candidate = &TREE_CHAIN (*candidate);
1911 /* Add the new function. */
1912 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1919 /* Called from find_final_overrider via dfs_walk. */
1922 dfs_find_final_overrider_pre (tree binfo, void *data)
1924 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1926 if (binfo == ffod->declaring_base)
1927 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1928 VEC_safe_push (tree, heap, ffod->path, binfo);
1934 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1936 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1937 VEC_pop (tree, ffod->path);
1942 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1943 FN and whose TREE_VALUE is the binfo for the base where the
1944 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1945 DERIVED) is the base object in which FN is declared. */
1948 find_final_overrider (tree derived, tree binfo, tree fn)
1950 find_final_overrider_data ffod;
1952 /* Getting this right is a little tricky. This is valid:
1954 struct S { virtual void f (); };
1955 struct T { virtual void f (); };
1956 struct U : public S, public T { };
1958 even though calling `f' in `U' is ambiguous. But,
1960 struct R { virtual void f(); };
1961 struct S : virtual public R { virtual void f (); };
1962 struct T : virtual public R { virtual void f (); };
1963 struct U : public S, public T { };
1965 is not -- there's no way to decide whether to put `S::f' or
1966 `T::f' in the vtable for `R'.
1968 The solution is to look at all paths to BINFO. If we find
1969 different overriders along any two, then there is a problem. */
1970 if (DECL_THUNK_P (fn))
1971 fn = THUNK_TARGET (fn);
1973 /* Determine the depth of the hierarchy. */
1975 ffod.declaring_base = binfo;
1976 ffod.candidates = NULL_TREE;
1977 ffod.path = VEC_alloc (tree, heap, 30);
1979 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1980 dfs_find_final_overrider_post, &ffod);
1982 VEC_free (tree, heap, ffod.path);
1984 /* If there was no winner, issue an error message. */
1985 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1986 return error_mark_node;
1988 return ffod.candidates;
1991 /* Return the index of the vcall offset for FN when TYPE is used as a
1995 get_vcall_index (tree fn, tree type)
1997 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
2001 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
2002 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2003 || same_signature_p (fn, p->purpose))
2006 /* There should always be an appropriate index. */
2010 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2011 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2012 corresponding position in the BINFO_VIRTUALS list. */
2015 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2023 tree overrider_fn, overrider_target;
2024 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2025 tree over_return, base_return;
2028 /* Find the nearest primary base (possibly binfo itself) which defines
2029 this function; this is the class the caller will convert to when
2030 calling FN through BINFO. */
2031 for (b = binfo; ; b = get_primary_binfo (b))
2034 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2037 /* The nearest definition is from a lost primary. */
2038 if (BINFO_LOST_PRIMARY_P (b))
2043 /* Find the final overrider. */
2044 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2045 if (overrider == error_mark_node)
2047 error ("no unique final overrider for %qD in %qT", target_fn, t);
2050 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2052 /* Check for adjusting covariant return types. */
2053 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2054 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2056 if (POINTER_TYPE_P (over_return)
2057 && TREE_CODE (over_return) == TREE_CODE (base_return)
2058 && CLASS_TYPE_P (TREE_TYPE (over_return))
2059 && CLASS_TYPE_P (TREE_TYPE (base_return))
2060 /* If the overrider is invalid, don't even try. */
2061 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2063 /* If FN is a covariant thunk, we must figure out the adjustment
2064 to the final base FN was converting to. As OVERRIDER_TARGET might
2065 also be converting to the return type of FN, we have to
2066 combine the two conversions here. */
2067 tree fixed_offset, virtual_offset;
2069 over_return = TREE_TYPE (over_return);
2070 base_return = TREE_TYPE (base_return);
2072 if (DECL_THUNK_P (fn))
2074 gcc_assert (DECL_RESULT_THUNK_P (fn));
2075 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2076 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2079 fixed_offset = virtual_offset = NULL_TREE;
2082 /* Find the equivalent binfo within the return type of the
2083 overriding function. We will want the vbase offset from
2085 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2087 else if (!same_type_ignoring_top_level_qualifiers_p
2088 (over_return, base_return))
2090 /* There was no existing virtual thunk (which takes
2091 precedence). So find the binfo of the base function's
2092 return type within the overriding function's return type.
2093 We cannot call lookup base here, because we're inside a
2094 dfs_walk, and will therefore clobber the BINFO_MARKED
2095 flags. Fortunately we know the covariancy is valid (it
2096 has already been checked), so we can just iterate along
2097 the binfos, which have been chained in inheritance graph
2098 order. Of course it is lame that we have to repeat the
2099 search here anyway -- we should really be caching pieces
2100 of the vtable and avoiding this repeated work. */
2101 tree thunk_binfo, base_binfo;
2103 /* Find the base binfo within the overriding function's
2104 return type. We will always find a thunk_binfo, except
2105 when the covariancy is invalid (which we will have
2106 already diagnosed). */
2107 for (base_binfo = TYPE_BINFO (base_return),
2108 thunk_binfo = TYPE_BINFO (over_return);
2110 thunk_binfo = TREE_CHAIN (thunk_binfo))
2111 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2112 BINFO_TYPE (base_binfo)))
2115 /* See if virtual inheritance is involved. */
2116 for (virtual_offset = thunk_binfo;
2118 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2119 if (BINFO_VIRTUAL_P (virtual_offset))
2123 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2125 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2129 /* We convert via virtual base. Adjust the fixed
2130 offset to be from there. */
2131 offset = size_diffop
2133 (ssizetype, BINFO_OFFSET (virtual_offset)));
2136 /* There was an existing fixed offset, this must be
2137 from the base just converted to, and the base the
2138 FN was thunking to. */
2139 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2141 fixed_offset = offset;
2145 if (fixed_offset || virtual_offset)
2146 /* Replace the overriding function with a covariant thunk. We
2147 will emit the overriding function in its own slot as
2149 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2150 fixed_offset, virtual_offset);
2153 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) ||
2154 !DECL_THUNK_P (fn));
2156 /* Assume that we will produce a thunk that convert all the way to
2157 the final overrider, and not to an intermediate virtual base. */
2158 virtual_base = NULL_TREE;
2160 /* See if we can convert to an intermediate virtual base first, and then
2161 use the vcall offset located there to finish the conversion. */
2162 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2164 /* If we find the final overrider, then we can stop
2166 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2167 BINFO_TYPE (TREE_VALUE (overrider))))
2170 /* If we find a virtual base, and we haven't yet found the
2171 overrider, then there is a virtual base between the
2172 declaring base (first_defn) and the final overrider. */
2173 if (BINFO_VIRTUAL_P (b))
2180 if (overrider_fn != overrider_target && !virtual_base)
2182 /* The ABI specifies that a covariant thunk includes a mangling
2183 for a this pointer adjustment. This-adjusting thunks that
2184 override a function from a virtual base have a vcall
2185 adjustment. When the virtual base in question is a primary
2186 virtual base, we know the adjustments are zero, (and in the
2187 non-covariant case, we would not use the thunk).
2188 Unfortunately we didn't notice this could happen, when
2189 designing the ABI and so never mandated that such a covariant
2190 thunk should be emitted. Because we must use the ABI mandated
2191 name, we must continue searching from the binfo where we
2192 found the most recent definition of the function, towards the
2193 primary binfo which first introduced the function into the
2194 vtable. If that enters a virtual base, we must use a vcall
2195 this-adjusting thunk. Bleah! */
2196 tree probe = first_defn;
2198 while ((probe = get_primary_binfo (probe))
2199 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2200 if (BINFO_VIRTUAL_P (probe))
2201 virtual_base = probe;
2204 /* Even if we find a virtual base, the correct delta is
2205 between the overrider and the binfo we're building a vtable
2207 goto virtual_covariant;
2210 /* Compute the constant adjustment to the `this' pointer. The
2211 `this' pointer, when this function is called, will point at BINFO
2212 (or one of its primary bases, which are at the same offset). */
2214 /* The `this' pointer needs to be adjusted from the declaration to
2215 the nearest virtual base. */
2216 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2217 convert (ssizetype, BINFO_OFFSET (first_defn)));
2219 /* If the nearest definition is in a lost primary, we don't need an
2220 entry in our vtable. Except possibly in a constructor vtable,
2221 if we happen to get our primary back. In that case, the offset
2222 will be zero, as it will be a primary base. */
2223 delta = size_zero_node;
2225 /* The `this' pointer needs to be adjusted from pointing to
2226 BINFO to pointing at the base where the final overrider
2229 delta = size_diffop (convert (ssizetype,
2230 BINFO_OFFSET (TREE_VALUE (overrider))),
2231 convert (ssizetype, BINFO_OFFSET (binfo)));
2233 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2236 BV_VCALL_INDEX (*virtuals)
2237 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2239 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2242 /* Called from modify_all_vtables via dfs_walk. */
2245 dfs_modify_vtables (tree binfo, void* data)
2247 tree t = (tree) data;
2252 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2253 /* A base without a vtable needs no modification, and its bases
2254 are uninteresting. */
2255 return dfs_skip_bases;
2257 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2258 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2259 /* Don't do the primary vtable, if it's new. */
2262 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2263 /* There's no need to modify the vtable for a non-virtual primary
2264 base; we're not going to use that vtable anyhow. We do still
2265 need to do this for virtual primary bases, as they could become
2266 non-primary in a construction vtable. */
2269 make_new_vtable (t, binfo);
2271 /* Now, go through each of the virtual functions in the virtual
2272 function table for BINFO. Find the final overrider, and update
2273 the BINFO_VIRTUALS list appropriately. */
2274 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2275 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2277 ix++, virtuals = TREE_CHAIN (virtuals),
2278 old_virtuals = TREE_CHAIN (old_virtuals))
2279 update_vtable_entry_for_fn (t,
2281 BV_FN (old_virtuals),
2287 /* Update all of the primary and secondary vtables for T. Create new
2288 vtables as required, and initialize their RTTI information. Each
2289 of the functions in VIRTUALS is declared in T and may override a
2290 virtual function from a base class; find and modify the appropriate
2291 entries to point to the overriding functions. Returns a list, in
2292 declaration order, of the virtual functions that are declared in T,
2293 but do not appear in the primary base class vtable, and which
2294 should therefore be appended to the end of the vtable for T. */
2297 modify_all_vtables (tree t, tree virtuals)
2299 tree binfo = TYPE_BINFO (t);
2302 /* Update all of the vtables. */
2303 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2305 /* Add virtual functions not already in our primary vtable. These
2306 will be both those introduced by this class, and those overridden
2307 from secondary bases. It does not include virtuals merely
2308 inherited from secondary bases. */
2309 for (fnsp = &virtuals; *fnsp; )
2311 tree fn = TREE_VALUE (*fnsp);
2313 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2314 || DECL_VINDEX (fn) == error_mark_node)
2316 /* We don't need to adjust the `this' pointer when
2317 calling this function. */
2318 BV_DELTA (*fnsp) = integer_zero_node;
2319 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2321 /* This is a function not already in our vtable. Keep it. */
2322 fnsp = &TREE_CHAIN (*fnsp);
2325 /* We've already got an entry for this function. Skip it. */
2326 *fnsp = TREE_CHAIN (*fnsp);
2332 /* Get the base virtual function declarations in T that have the
2336 get_basefndecls (tree name, tree t)
2339 tree base_fndecls = NULL_TREE;
2340 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2343 /* Find virtual functions in T with the indicated NAME. */
2344 i = lookup_fnfields_1 (t, name);
2346 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2348 methods = OVL_NEXT (methods))
2350 tree method = OVL_CURRENT (methods);
2352 if (TREE_CODE (method) == FUNCTION_DECL
2353 && DECL_VINDEX (method))
2354 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2358 return base_fndecls;
2360 for (i = 0; i < n_baseclasses; i++)
2362 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2363 base_fndecls = chainon (get_basefndecls (name, basetype),
2367 return base_fndecls;
2370 /* If this declaration supersedes the declaration of
2371 a method declared virtual in the base class, then
2372 mark this field as being virtual as well. */
2375 check_for_override (tree decl, tree ctype)
2377 if (TREE_CODE (decl) == TEMPLATE_DECL)
2378 /* In [temp.mem] we have:
2380 A specialization of a member function template does not
2381 override a virtual function from a base class. */
2383 if ((DECL_DESTRUCTOR_P (decl)
2384 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2385 || DECL_CONV_FN_P (decl))
2386 && look_for_overrides (ctype, decl)
2387 && !DECL_STATIC_FUNCTION_P (decl))
2388 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2389 the error_mark_node so that we know it is an overriding
2391 DECL_VINDEX (decl) = decl;
2393 if (DECL_VIRTUAL_P (decl))
2395 if (!DECL_VINDEX (decl))
2396 DECL_VINDEX (decl) = error_mark_node;
2397 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2401 /* Warn about hidden virtual functions that are not overridden in t.
2402 We know that constructors and destructors don't apply. */
2405 warn_hidden (tree t)
2407 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2411 /* We go through each separately named virtual function. */
2412 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2413 VEC_iterate (tree, method_vec, i, fns);
2424 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2425 have the same name. Figure out what name that is. */
2426 name = DECL_NAME (OVL_CURRENT (fns));
2427 /* There are no possibly hidden functions yet. */
2428 base_fndecls = NULL_TREE;
2429 /* Iterate through all of the base classes looking for possibly
2430 hidden functions. */
2431 for (binfo = TYPE_BINFO (t), j = 0;
2432 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2434 tree basetype = BINFO_TYPE (base_binfo);
2435 base_fndecls = chainon (get_basefndecls (name, basetype),
2439 /* If there are no functions to hide, continue. */
2443 /* Remove any overridden functions. */
2444 for (fn = fns; fn; fn = OVL_NEXT (fn))
2446 fndecl = OVL_CURRENT (fn);
2447 if (DECL_VINDEX (fndecl))
2449 tree *prev = &base_fndecls;
2452 /* If the method from the base class has the same
2453 signature as the method from the derived class, it
2454 has been overridden. */
2455 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2456 *prev = TREE_CHAIN (*prev);
2458 prev = &TREE_CHAIN (*prev);
2462 /* Now give a warning for all base functions without overriders,
2463 as they are hidden. */
2464 while (base_fndecls)
2466 /* Here we know it is a hider, and no overrider exists. */
2467 warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls));
2468 warning (OPT_Woverloaded_virtual, " by %q+D", fns);
2469 base_fndecls = TREE_CHAIN (base_fndecls);
2474 /* Check for things that are invalid. There are probably plenty of other
2475 things we should check for also. */
2478 finish_struct_anon (tree t)
2482 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2484 if (TREE_STATIC (field))
2486 if (TREE_CODE (field) != FIELD_DECL)
2489 if (DECL_NAME (field) == NULL_TREE
2490 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2492 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
2493 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2494 for (; elt; elt = TREE_CHAIN (elt))
2496 /* We're generally only interested in entities the user
2497 declared, but we also find nested classes by noticing
2498 the TYPE_DECL that we create implicitly. You're
2499 allowed to put one anonymous union inside another,
2500 though, so we explicitly tolerate that. We use
2501 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2502 we also allow unnamed types used for defining fields. */
2503 if (DECL_ARTIFICIAL (elt)
2504 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2505 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2508 if (TREE_CODE (elt) != FIELD_DECL)
2511 permerror (input_location, "%q+#D invalid; an anonymous union can "
2512 "only have non-static data members", elt);
2514 permerror (input_location, "%q+#D invalid; an anonymous struct can "
2515 "only have non-static data members", elt);
2519 if (TREE_PRIVATE (elt))
2522 permerror (input_location, "private member %q+#D in anonymous union", elt);
2524 permerror (input_location, "private member %q+#D in anonymous struct", elt);
2526 else if (TREE_PROTECTED (elt))
2529 permerror (input_location, "protected member %q+#D in anonymous union", elt);
2531 permerror (input_location, "protected member %q+#D in anonymous struct", elt);
2534 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2535 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2541 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2542 will be used later during class template instantiation.
2543 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2544 a non-static member data (FIELD_DECL), a member function
2545 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2546 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2547 When FRIEND_P is nonzero, T is either a friend class
2548 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2549 (FUNCTION_DECL, TEMPLATE_DECL). */
2552 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2554 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2555 if (CLASSTYPE_TEMPLATE_INFO (type))
2556 CLASSTYPE_DECL_LIST (type)
2557 = tree_cons (friend_p ? NULL_TREE : type,
2558 t, CLASSTYPE_DECL_LIST (type));
2561 /* Create default constructors, assignment operators, and so forth for
2562 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2563 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2564 the class cannot have a default constructor, copy constructor
2565 taking a const reference argument, or an assignment operator taking
2566 a const reference, respectively. */
2569 add_implicitly_declared_members (tree t,
2570 int cant_have_const_cctor,
2571 int cant_have_const_assignment)
2574 if (!CLASSTYPE_DESTRUCTORS (t))
2576 /* In general, we create destructors lazily. */
2577 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2578 /* However, if the implicit destructor is non-trivial
2579 destructor, we sometimes have to create it at this point. */
2580 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2584 if (TYPE_FOR_JAVA (t))
2585 /* If this a Java class, any non-trivial destructor is
2586 invalid, even if compiler-generated. Therefore, if the
2587 destructor is non-trivial we create it now. */
2595 /* If the implicit destructor will be virtual, then we must
2596 generate it now because (unfortunately) we do not
2597 generate virtual tables lazily. */
2598 binfo = TYPE_BINFO (t);
2599 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2604 base_type = BINFO_TYPE (base_binfo);
2605 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2606 if (dtor && DECL_VIRTUAL_P (dtor))
2614 /* If we can't get away with being lazy, generate the destructor
2617 lazily_declare_fn (sfk_destructor, t);
2623 If there is no user-declared constructor for a class, a default
2624 constructor is implicitly declared. */
2625 if (! TYPE_HAS_USER_CONSTRUCTOR (t))
2627 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2628 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2633 If a class definition does not explicitly declare a copy
2634 constructor, one is declared implicitly. */
2635 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2637 TYPE_HAS_INIT_REF (t) = 1;
2638 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2639 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2642 /* If there is no assignment operator, one will be created if and
2643 when it is needed. For now, just record whether or not the type
2644 of the parameter to the assignment operator will be a const or
2645 non-const reference. */
2646 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2648 TYPE_HAS_ASSIGN_REF (t) = 1;
2649 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2650 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2654 /* Subroutine of finish_struct_1. Recursively count the number of fields
2655 in TYPE, including anonymous union members. */
2658 count_fields (tree fields)
2662 for (x = fields; x; x = TREE_CHAIN (x))
2664 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2665 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2672 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2673 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2676 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2679 for (x = fields; x; x = TREE_CHAIN (x))
2681 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2682 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2684 field_vec->elts[idx++] = x;
2689 /* FIELD is a bit-field. We are finishing the processing for its
2690 enclosing type. Issue any appropriate messages and set appropriate
2691 flags. Returns false if an error has been diagnosed. */
2694 check_bitfield_decl (tree field)
2696 tree type = TREE_TYPE (field);
2699 /* Extract the declared width of the bitfield, which has been
2700 temporarily stashed in DECL_INITIAL. */
2701 w = DECL_INITIAL (field);
2702 gcc_assert (w != NULL_TREE);
2703 /* Remove the bit-field width indicator so that the rest of the
2704 compiler does not treat that value as an initializer. */
2705 DECL_INITIAL (field) = NULL_TREE;
2707 /* Detect invalid bit-field type. */
2708 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (type))
2710 error ("bit-field %q+#D with non-integral type", field);
2711 w = error_mark_node;
2715 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2718 /* detect invalid field size. */
2719 w = integral_constant_value (w);
2721 if (TREE_CODE (w) != INTEGER_CST)
2723 error ("bit-field %q+D width not an integer constant", field);
2724 w = error_mark_node;
2726 else if (tree_int_cst_sgn (w) < 0)
2728 error ("negative width in bit-field %q+D", field);
2729 w = error_mark_node;
2731 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2733 error ("zero width for bit-field %q+D", field);
2734 w = error_mark_node;
2736 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2737 && TREE_CODE (type) != ENUMERAL_TYPE
2738 && TREE_CODE (type) != BOOLEAN_TYPE)
2739 warning (0, "width of %q+D exceeds its type", field);
2740 else if (TREE_CODE (type) == ENUMERAL_TYPE
2741 && (0 > compare_tree_int (w,
2742 tree_int_cst_min_precision
2743 (TYPE_MIN_VALUE (type),
2744 TYPE_UNSIGNED (type)))
2745 || 0 > compare_tree_int (w,
2746 tree_int_cst_min_precision
2747 (TYPE_MAX_VALUE (type),
2748 TYPE_UNSIGNED (type)))))
2749 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2752 if (w != error_mark_node)
2754 DECL_SIZE (field) = convert (bitsizetype, w);
2755 DECL_BIT_FIELD (field) = 1;
2760 /* Non-bit-fields are aligned for their type. */
2761 DECL_BIT_FIELD (field) = 0;
2762 CLEAR_DECL_C_BIT_FIELD (field);
2767 /* FIELD is a non bit-field. We are finishing the processing for its
2768 enclosing type T. Issue any appropriate messages and set appropriate
2772 check_field_decl (tree field,
2774 int* cant_have_const_ctor,
2775 int* no_const_asn_ref,
2776 int* any_default_members)
2778 tree type = strip_array_types (TREE_TYPE (field));
2780 /* An anonymous union cannot contain any fields which would change
2781 the settings of CANT_HAVE_CONST_CTOR and friends. */
2782 if (ANON_UNION_TYPE_P (type))
2784 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2785 structs. So, we recurse through their fields here. */
2786 else if (ANON_AGGR_TYPE_P (type))
2790 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2791 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2792 check_field_decl (fields, t, cant_have_const_ctor,
2793 no_const_asn_ref, any_default_members);
2795 /* Check members with class type for constructors, destructors,
2797 else if (CLASS_TYPE_P (type))
2799 /* Never let anything with uninheritable virtuals
2800 make it through without complaint. */
2801 abstract_virtuals_error (field, type);
2803 if (TREE_CODE (t) == UNION_TYPE)
2805 if (TYPE_NEEDS_CONSTRUCTING (type))
2806 error ("member %q+#D with constructor not allowed in union",
2808 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2809 error ("member %q+#D with destructor not allowed in union", field);
2810 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2811 error ("member %q+#D with copy assignment operator not allowed in union",
2816 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2817 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2818 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2819 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2820 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2821 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (type);
2824 if (!TYPE_HAS_CONST_INIT_REF (type))
2825 *cant_have_const_ctor = 1;
2827 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2828 *no_const_asn_ref = 1;
2830 if (DECL_INITIAL (field) != NULL_TREE)
2832 /* `build_class_init_list' does not recognize
2834 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2835 error ("multiple fields in union %qT initialized", t);
2836 *any_default_members = 1;
2840 /* Check the data members (both static and non-static), class-scoped
2841 typedefs, etc., appearing in the declaration of T. Issue
2842 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2843 declaration order) of access declarations; each TREE_VALUE in this
2844 list is a USING_DECL.
2846 In addition, set the following flags:
2849 The class is empty, i.e., contains no non-static data members.
2851 CANT_HAVE_CONST_CTOR_P
2852 This class cannot have an implicitly generated copy constructor
2853 taking a const reference.
2855 CANT_HAVE_CONST_ASN_REF
2856 This class cannot have an implicitly generated assignment
2857 operator taking a const reference.
2859 All of these flags should be initialized before calling this
2862 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2863 fields can be added by adding to this chain. */
2866 check_field_decls (tree t, tree *access_decls,
2867 int *cant_have_const_ctor_p,
2868 int *no_const_asn_ref_p)
2873 int any_default_members;
2876 /* Assume there are no access declarations. */
2877 *access_decls = NULL_TREE;
2878 /* Assume this class has no pointer members. */
2879 has_pointers = false;
2880 /* Assume none of the members of this class have default
2882 any_default_members = 0;
2884 for (field = &TYPE_FIELDS (t); *field; field = next)
2887 tree type = TREE_TYPE (x);
2889 next = &TREE_CHAIN (x);
2891 if (TREE_CODE (x) == USING_DECL)
2893 /* Prune the access declaration from the list of fields. */
2894 *field = TREE_CHAIN (x);
2896 /* Save the access declarations for our caller. */
2897 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2899 /* Since we've reset *FIELD there's no reason to skip to the
2905 if (TREE_CODE (x) == TYPE_DECL
2906 || TREE_CODE (x) == TEMPLATE_DECL)
2909 /* If we've gotten this far, it's a data member, possibly static,
2910 or an enumerator. */
2911 DECL_CONTEXT (x) = t;
2913 /* When this goes into scope, it will be a non-local reference. */
2914 DECL_NONLOCAL (x) = 1;
2916 if (TREE_CODE (t) == UNION_TYPE)
2920 If a union contains a static data member, or a member of
2921 reference type, the program is ill-formed. */
2922 if (TREE_CODE (x) == VAR_DECL)
2924 error ("%q+D may not be static because it is a member of a union", x);
2927 if (TREE_CODE (type) == REFERENCE_TYPE)
2929 error ("%q+D may not have reference type %qT because"
2930 " it is a member of a union",
2936 /* Perform error checking that did not get done in
2938 if (TREE_CODE (type) == FUNCTION_TYPE)
2940 error ("field %q+D invalidly declared function type", x);
2941 type = build_pointer_type (type);
2942 TREE_TYPE (x) = type;
2944 else if (TREE_CODE (type) == METHOD_TYPE)
2946 error ("field %q+D invalidly declared method type", x);
2947 type = build_pointer_type (type);
2948 TREE_TYPE (x) = type;
2951 if (type == error_mark_node)
2954 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2957 /* Now it can only be a FIELD_DECL. */
2959 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2960 CLASSTYPE_NON_AGGREGATE (t) = 1;
2962 /* If this is of reference type, check if it needs an init. */
2963 if (TREE_CODE (type) == REFERENCE_TYPE)
2965 CLASSTYPE_NON_POD_P (t) = 1;
2966 if (DECL_INITIAL (x) == NULL_TREE)
2967 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2969 /* ARM $12.6.2: [A member initializer list] (or, for an
2970 aggregate, initialization by a brace-enclosed list) is the
2971 only way to initialize nonstatic const and reference
2973 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2976 type = strip_array_types (type);
2978 if (TYPE_PACKED (t))
2980 if (!pod_type_p (type) && !TYPE_PACKED (type))
2984 "ignoring packed attribute because of unpacked non-POD field %q+#D",
2988 else if (DECL_C_BIT_FIELD (x)
2989 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
2990 DECL_PACKED (x) = 1;
2993 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2994 /* We don't treat zero-width bitfields as making a class
2999 /* The class is non-empty. */
3000 CLASSTYPE_EMPTY_P (t) = 0;
3001 /* The class is not even nearly empty. */
3002 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3003 /* If one of the data members contains an empty class,
3005 if (CLASS_TYPE_P (type)
3006 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3007 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
3010 /* This is used by -Weffc++ (see below). Warn only for pointers
3011 to members which might hold dynamic memory. So do not warn
3012 for pointers to functions or pointers to members. */
3013 if (TYPE_PTR_P (type)
3014 && !TYPE_PTRFN_P (type)
3015 && !TYPE_PTR_TO_MEMBER_P (type))
3016 has_pointers = true;
3018 if (CLASS_TYPE_P (type))
3020 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3021 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3022 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3023 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3026 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3027 CLASSTYPE_HAS_MUTABLE (t) = 1;
3029 if (! pod_type_p (type))
3030 /* DR 148 now allows pointers to members (which are POD themselves),
3031 to be allowed in POD structs. */
3032 CLASSTYPE_NON_POD_P (t) = 1;
3034 if (! zero_init_p (type))
3035 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3037 /* If any field is const, the structure type is pseudo-const. */
3038 if (CP_TYPE_CONST_P (type))
3040 C_TYPE_FIELDS_READONLY (t) = 1;
3041 if (DECL_INITIAL (x) == NULL_TREE)
3042 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3044 /* ARM $12.6.2: [A member initializer list] (or, for an
3045 aggregate, initialization by a brace-enclosed list) is the
3046 only way to initialize nonstatic const and reference
3048 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3050 /* A field that is pseudo-const makes the structure likewise. */
3051 else if (CLASS_TYPE_P (type))
3053 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3054 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3055 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3056 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3059 /* Core issue 80: A nonstatic data member is required to have a
3060 different name from the class iff the class has a
3061 user-declared constructor. */
3062 if (constructor_name_p (DECL_NAME (x), t)
3063 && TYPE_HAS_USER_CONSTRUCTOR (t))
3064 permerror (input_location, "field %q+#D with same name as class", x);
3066 /* We set DECL_C_BIT_FIELD in grokbitfield.
3067 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3068 if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x))
3069 check_field_decl (x, t,
3070 cant_have_const_ctor_p,
3072 &any_default_members);
3075 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3076 it should also define a copy constructor and an assignment operator to
3077 implement the correct copy semantic (deep vs shallow, etc.). As it is
3078 not feasible to check whether the constructors do allocate dynamic memory
3079 and store it within members, we approximate the warning like this:
3081 -- Warn only if there are members which are pointers
3082 -- Warn only if there is a non-trivial constructor (otherwise,
3083 there cannot be memory allocated).
3084 -- Warn only if there is a non-trivial destructor. We assume that the
3085 user at least implemented the cleanup correctly, and a destructor
3086 is needed to free dynamic memory.
3088 This seems enough for practical purposes. */
3091 && TYPE_HAS_USER_CONSTRUCTOR (t)
3092 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3093 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3095 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3097 if (! TYPE_HAS_INIT_REF (t))
3099 warning (OPT_Weffc__,
3100 " but does not override %<%T(const %T&)%>", t, t);
3101 if (!TYPE_HAS_ASSIGN_REF (t))
3102 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3104 else if (! TYPE_HAS_ASSIGN_REF (t))
3105 warning (OPT_Weffc__,
3106 " but does not override %<operator=(const %T&)%>", t);
3109 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3111 TYPE_PACKED (t) = 0;
3113 /* Check anonymous struct/anonymous union fields. */
3114 finish_struct_anon (t);
3116 /* We've built up the list of access declarations in reverse order.
3118 *access_decls = nreverse (*access_decls);
3121 /* If TYPE is an empty class type, records its OFFSET in the table of
3125 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3129 if (!is_empty_class (type))
3132 /* Record the location of this empty object in OFFSETS. */
3133 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3135 n = splay_tree_insert (offsets,
3136 (splay_tree_key) offset,
3137 (splay_tree_value) NULL_TREE);
3138 n->value = ((splay_tree_value)
3139 tree_cons (NULL_TREE,
3146 /* Returns nonzero if TYPE is an empty class type and there is
3147 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3150 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3155 if (!is_empty_class (type))
3158 /* Record the location of this empty object in OFFSETS. */
3159 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3163 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3164 if (same_type_p (TREE_VALUE (t), type))
3170 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3171 F for every subobject, passing it the type, offset, and table of
3172 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3175 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3176 than MAX_OFFSET will not be walked.
3178 If F returns a nonzero value, the traversal ceases, and that value
3179 is returned. Otherwise, returns zero. */
3182 walk_subobject_offsets (tree type,
3183 subobject_offset_fn f,
3190 tree type_binfo = NULL_TREE;
3192 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3194 if (max_offset && INT_CST_LT (max_offset, offset))
3197 if (type == error_mark_node)
3202 if (abi_version_at_least (2))
3204 type = BINFO_TYPE (type);
3207 if (CLASS_TYPE_P (type))
3213 /* Avoid recursing into objects that are not interesting. */
3214 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3217 /* Record the location of TYPE. */
3218 r = (*f) (type, offset, offsets);
3222 /* Iterate through the direct base classes of TYPE. */
3224 type_binfo = TYPE_BINFO (type);
3225 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3229 if (abi_version_at_least (2)
3230 && BINFO_VIRTUAL_P (binfo))
3234 && BINFO_VIRTUAL_P (binfo)
3235 && !BINFO_PRIMARY_P (binfo))
3238 if (!abi_version_at_least (2))
3239 binfo_offset = size_binop (PLUS_EXPR,
3241 BINFO_OFFSET (binfo));
3245 /* We cannot rely on BINFO_OFFSET being set for the base
3246 class yet, but the offsets for direct non-virtual
3247 bases can be calculated by going back to the TYPE. */
3248 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3249 binfo_offset = size_binop (PLUS_EXPR,
3251 BINFO_OFFSET (orig_binfo));
3254 r = walk_subobject_offsets (binfo,
3259 (abi_version_at_least (2)
3260 ? /*vbases_p=*/0 : vbases_p));
3265 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3268 VEC(tree,gc) *vbases;
3270 /* Iterate through the virtual base classes of TYPE. In G++
3271 3.2, we included virtual bases in the direct base class
3272 loop above, which results in incorrect results; the
3273 correct offsets for virtual bases are only known when
3274 working with the most derived type. */
3276 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3277 VEC_iterate (tree, vbases, ix, binfo); ix++)
3279 r = walk_subobject_offsets (binfo,
3281 size_binop (PLUS_EXPR,
3283 BINFO_OFFSET (binfo)),
3292 /* We still have to walk the primary base, if it is
3293 virtual. (If it is non-virtual, then it was walked
3295 tree vbase = get_primary_binfo (type_binfo);
3297 if (vbase && BINFO_VIRTUAL_P (vbase)
3298 && BINFO_PRIMARY_P (vbase)
3299 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3301 r = (walk_subobject_offsets
3303 offsets, max_offset, /*vbases_p=*/0));
3310 /* Iterate through the fields of TYPE. */
3311 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3312 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3316 if (abi_version_at_least (2))
3317 field_offset = byte_position (field);
3319 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3320 field_offset = DECL_FIELD_OFFSET (field);
3322 r = walk_subobject_offsets (TREE_TYPE (field),
3324 size_binop (PLUS_EXPR,
3334 else if (TREE_CODE (type) == ARRAY_TYPE)
3336 tree element_type = strip_array_types (type);
3337 tree domain = TYPE_DOMAIN (type);
3340 /* Avoid recursing into objects that are not interesting. */
3341 if (!CLASS_TYPE_P (element_type)
3342 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3345 /* Step through each of the elements in the array. */
3346 for (index = size_zero_node;
3347 /* G++ 3.2 had an off-by-one error here. */
3348 (abi_version_at_least (2)
3349 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3350 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3351 index = size_binop (PLUS_EXPR, index, size_one_node))
3353 r = walk_subobject_offsets (TREE_TYPE (type),
3361 offset = size_binop (PLUS_EXPR, offset,
3362 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3363 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3364 there's no point in iterating through the remaining
3365 elements of the array. */
3366 if (max_offset && INT_CST_LT (max_offset, offset))
3374 /* Record all of the empty subobjects of TYPE (either a type or a
3375 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3376 is being placed at OFFSET; otherwise, it is a base class that is
3377 being placed at OFFSET. */
3380 record_subobject_offsets (tree type,
3383 bool is_data_member)
3386 /* If recording subobjects for a non-static data member or a
3387 non-empty base class , we do not need to record offsets beyond
3388 the size of the biggest empty class. Additional data members
3389 will go at the end of the class. Additional base classes will go
3390 either at offset zero (if empty, in which case they cannot
3391 overlap with offsets past the size of the biggest empty class) or
3392 at the end of the class.
3394 However, if we are placing an empty base class, then we must record
3395 all offsets, as either the empty class is at offset zero (where
3396 other empty classes might later be placed) or at the end of the
3397 class (where other objects might then be placed, so other empty
3398 subobjects might later overlap). */
3400 || !is_empty_class (BINFO_TYPE (type)))
3401 max_offset = sizeof_biggest_empty_class;
3403 max_offset = NULL_TREE;
3404 walk_subobject_offsets (type, record_subobject_offset, offset,
3405 offsets, max_offset, is_data_member);
3408 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3409 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3410 virtual bases of TYPE are examined. */
3413 layout_conflict_p (tree type,
3418 splay_tree_node max_node;
3420 /* Get the node in OFFSETS that indicates the maximum offset where
3421 an empty subobject is located. */
3422 max_node = splay_tree_max (offsets);
3423 /* If there aren't any empty subobjects, then there's no point in
3424 performing this check. */
3428 return walk_subobject_offsets (type, check_subobject_offset, offset,
3429 offsets, (tree) (max_node->key),
3433 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3434 non-static data member of the type indicated by RLI. BINFO is the
3435 binfo corresponding to the base subobject, OFFSETS maps offsets to
3436 types already located at those offsets. This function determines
3437 the position of the DECL. */
3440 layout_nonempty_base_or_field (record_layout_info rli,
3445 tree offset = NULL_TREE;
3451 /* For the purposes of determining layout conflicts, we want to
3452 use the class type of BINFO; TREE_TYPE (DECL) will be the
3453 CLASSTYPE_AS_BASE version, which does not contain entries for
3454 zero-sized bases. */
3455 type = TREE_TYPE (binfo);
3460 type = TREE_TYPE (decl);
3464 /* Try to place the field. It may take more than one try if we have
3465 a hard time placing the field without putting two objects of the
3466 same type at the same address. */
3469 struct record_layout_info_s old_rli = *rli;
3471 /* Place this field. */
3472 place_field (rli, decl);
3473 offset = byte_position (decl);
3475 /* We have to check to see whether or not there is already
3476 something of the same type at the offset we're about to use.
3477 For example, consider:
3480 struct T : public S { int i; };
3481 struct U : public S, public T {};
3483 Here, we put S at offset zero in U. Then, we can't put T at
3484 offset zero -- its S component would be at the same address
3485 as the S we already allocated. So, we have to skip ahead.
3486 Since all data members, including those whose type is an
3487 empty class, have nonzero size, any overlap can happen only
3488 with a direct or indirect base-class -- it can't happen with
3490 /* In a union, overlap is permitted; all members are placed at
3492 if (TREE_CODE (rli->t) == UNION_TYPE)
3494 /* G++ 3.2 did not check for overlaps when placing a non-empty
3496 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3498 if (layout_conflict_p (field_p ? type : binfo, offset,
3501 /* Strip off the size allocated to this field. That puts us
3502 at the first place we could have put the field with
3503 proper alignment. */
3506 /* Bump up by the alignment required for the type. */
3508 = size_binop (PLUS_EXPR, rli->bitpos,
3510 ? CLASSTYPE_ALIGN (type)
3511 : TYPE_ALIGN (type)));
3512 normalize_rli (rli);
3515 /* There was no conflict. We're done laying out this field. */
3519 /* Now that we know where it will be placed, update its
3521 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3522 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3523 this point because their BINFO_OFFSET is copied from another
3524 hierarchy. Therefore, we may not need to add the entire
3526 propagate_binfo_offsets (binfo,
3527 size_diffop (convert (ssizetype, offset),
3529 BINFO_OFFSET (binfo))));
3532 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3535 empty_base_at_nonzero_offset_p (tree type,
3537 splay_tree offsets ATTRIBUTE_UNUSED)
3539 return is_empty_class (type) && !integer_zerop (offset);
3542 /* Layout the empty base BINFO. EOC indicates the byte currently just
3543 past the end of the class, and should be correctly aligned for a
3544 class of the type indicated by BINFO; OFFSETS gives the offsets of
3545 the empty bases allocated so far. T is the most derived
3546 type. Return nonzero iff we added it at the end. */
3549 layout_empty_base (record_layout_info rli, tree binfo,
3550 tree eoc, splay_tree offsets)
3553 tree basetype = BINFO_TYPE (binfo);
3556 /* This routine should only be used for empty classes. */
3557 gcc_assert (is_empty_class (basetype));
3558 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3560 if (!integer_zerop (BINFO_OFFSET (binfo)))
3562 if (abi_version_at_least (2))
3563 propagate_binfo_offsets
3564 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3567 "offset of empty base %qT may not be ABI-compliant and may"
3568 "change in a future version of GCC",
3569 BINFO_TYPE (binfo));
3572 /* This is an empty base class. We first try to put it at offset
3574 if (layout_conflict_p (binfo,
3575 BINFO_OFFSET (binfo),
3579 /* That didn't work. Now, we move forward from the next
3580 available spot in the class. */
3582 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3585 if (!layout_conflict_p (binfo,
3586 BINFO_OFFSET (binfo),
3589 /* We finally found a spot where there's no overlap. */
3592 /* There's overlap here, too. Bump along to the next spot. */
3593 propagate_binfo_offsets (binfo, alignment);
3597 if (CLASSTYPE_USER_ALIGN (basetype))
3599 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype));
3601 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype));
3602 TYPE_USER_ALIGN (rli->t) = 1;
3608 /* Layout the base given by BINFO in the class indicated by RLI.
3609 *BASE_ALIGN is a running maximum of the alignments of
3610 any base class. OFFSETS gives the location of empty base
3611 subobjects. T is the most derived type. Return nonzero if the new
3612 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3613 *NEXT_FIELD, unless BINFO is for an empty base class.
3615 Returns the location at which the next field should be inserted. */
3618 build_base_field (record_layout_info rli, tree binfo,
3619 splay_tree offsets, tree *next_field)
3622 tree basetype = BINFO_TYPE (binfo);
3624 if (!COMPLETE_TYPE_P (basetype))
3625 /* This error is now reported in xref_tag, thus giving better
3626 location information. */
3629 /* Place the base class. */
3630 if (!is_empty_class (basetype))
3634 /* The containing class is non-empty because it has a non-empty
3636 CLASSTYPE_EMPTY_P (t) = 0;
3638 /* Create the FIELD_DECL. */
3639 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3640 DECL_ARTIFICIAL (decl) = 1;
3641 DECL_IGNORED_P (decl) = 1;
3642 DECL_FIELD_CONTEXT (decl) = t;
3643 if (CLASSTYPE_AS_BASE (basetype))
3645 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3646 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3647 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3648 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3649 DECL_MODE (decl) = TYPE_MODE (basetype);
3650 DECL_FIELD_IS_BASE (decl) = 1;
3652 /* Try to place the field. It may take more than one try if we
3653 have a hard time placing the field without putting two
3654 objects of the same type at the same address. */
3655 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3656 /* Add the new FIELD_DECL to the list of fields for T. */
3657 TREE_CHAIN (decl) = *next_field;
3659 next_field = &TREE_CHAIN (decl);
3667 /* On some platforms (ARM), even empty classes will not be
3669 eoc = round_up (rli_size_unit_so_far (rli),
3670 CLASSTYPE_ALIGN_UNIT (basetype));
3671 atend = layout_empty_base (rli, binfo, eoc, offsets);
3672 /* A nearly-empty class "has no proper base class that is empty,
3673 not morally virtual, and at an offset other than zero." */
3674 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3677 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3678 /* The check above (used in G++ 3.2) is insufficient because
3679 an empty class placed at offset zero might itself have an
3680 empty base at a nonzero offset. */
3681 else if (walk_subobject_offsets (basetype,
3682 empty_base_at_nonzero_offset_p,
3685 /*max_offset=*/NULL_TREE,
3688 if (abi_version_at_least (2))
3689 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3692 "class %qT will be considered nearly empty in a "
3693 "future version of GCC", t);
3697 /* We do not create a FIELD_DECL for empty base classes because
3698 it might overlap some other field. We want to be able to
3699 create CONSTRUCTORs for the class by iterating over the
3700 FIELD_DECLs, and the back end does not handle overlapping
3703 /* An empty virtual base causes a class to be non-empty
3704 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3705 here because that was already done when the virtual table
3706 pointer was created. */
3709 /* Record the offsets of BINFO and its base subobjects. */
3710 record_subobject_offsets (binfo,
3711 BINFO_OFFSET (binfo),
3713 /*is_data_member=*/false);
3718 /* Layout all of the non-virtual base classes. Record empty
3719 subobjects in OFFSETS. T is the most derived type. Return nonzero
3720 if the type cannot be nearly empty. The fields created
3721 corresponding to the base classes will be inserted at
3725 build_base_fields (record_layout_info rli,
3726 splay_tree offsets, tree *next_field)
3728 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3731 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3734 /* The primary base class is always allocated first. */
3735 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3736 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3737 offsets, next_field);
3739 /* Now allocate the rest of the bases. */
3740 for (i = 0; i < n_baseclasses; ++i)
3744 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3746 /* The primary base was already allocated above, so we don't
3747 need to allocate it again here. */
3748 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3751 /* Virtual bases are added at the end (a primary virtual base
3752 will have already been added). */
3753 if (BINFO_VIRTUAL_P (base_binfo))
3756 next_field = build_base_field (rli, base_binfo,
3757 offsets, next_field);
3761 /* Go through the TYPE_METHODS of T issuing any appropriate
3762 diagnostics, figuring out which methods override which other
3763 methods, and so forth. */
3766 check_methods (tree t)
3770 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3772 check_for_override (x, t);
3773 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3774 error ("initializer specified for non-virtual method %q+D", x);
3775 /* The name of the field is the original field name
3776 Save this in auxiliary field for later overloading. */
3777 if (DECL_VINDEX (x))
3779 TYPE_POLYMORPHIC_P (t) = 1;
3780 if (DECL_PURE_VIRTUAL_P (x))
3781 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3783 /* All user-provided destructors are non-trivial. */
3784 if (DECL_DESTRUCTOR_P (x) && !DECL_DEFAULTED_FN (x))
3785 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3789 /* FN is a constructor or destructor. Clone the declaration to create
3790 a specialized in-charge or not-in-charge version, as indicated by
3794 build_clone (tree fn, tree name)
3799 /* Copy the function. */
3800 clone = copy_decl (fn);
3801 /* Remember where this function came from. */
3802 DECL_CLONED_FUNCTION (clone) = fn;
3803 DECL_ABSTRACT_ORIGIN (clone) = fn;
3804 /* Reset the function name. */
3805 DECL_NAME (clone) = name;
3806 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3807 /* There's no pending inline data for this function. */
3808 DECL_PENDING_INLINE_INFO (clone) = NULL;
3809 DECL_PENDING_INLINE_P (clone) = 0;
3810 /* And it hasn't yet been deferred. */
3811 DECL_DEFERRED_FN (clone) = 0;
3813 /* The base-class destructor is not virtual. */
3814 if (name == base_dtor_identifier)
3816 DECL_VIRTUAL_P (clone) = 0;
3817 if (TREE_CODE (clone) != TEMPLATE_DECL)
3818 DECL_VINDEX (clone) = NULL_TREE;
3821 /* If there was an in-charge parameter, drop it from the function
3823 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3829 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3830 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3831 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3832 /* Skip the `this' parameter. */
3833 parmtypes = TREE_CHAIN (parmtypes);
3834 /* Skip the in-charge parameter. */
3835 parmtypes = TREE_CHAIN (parmtypes);
3836 /* And the VTT parm, in a complete [cd]tor. */
3837 if (DECL_HAS_VTT_PARM_P (fn)
3838 && ! DECL_NEEDS_VTT_PARM_P (clone))
3839 parmtypes = TREE_CHAIN (parmtypes);
3840 /* If this is subobject constructor or destructor, add the vtt
3843 = build_method_type_directly (basetype,
3844 TREE_TYPE (TREE_TYPE (clone)),
3847 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3850 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3851 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3854 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3855 aren't function parameters; those are the template parameters. */
3856 if (TREE_CODE (clone) != TEMPLATE_DECL)
3858 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3859 /* Remove the in-charge parameter. */
3860 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3862 TREE_CHAIN (DECL_ARGUMENTS (clone))
3863 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3864 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3866 /* And the VTT parm, in a complete [cd]tor. */
3867 if (DECL_HAS_VTT_PARM_P (fn))
3869 if (DECL_NEEDS_VTT_PARM_P (clone))
3870 DECL_HAS_VTT_PARM_P (clone) = 1;
3873 TREE_CHAIN (DECL_ARGUMENTS (clone))
3874 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3875 DECL_HAS_VTT_PARM_P (clone) = 0;
3879 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3881 DECL_CONTEXT (parms) = clone;
3882 cxx_dup_lang_specific_decl (parms);
3886 /* Create the RTL for this function. */
3887 SET_DECL_RTL (clone, NULL_RTX);
3888 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3890 /* Make it easy to find the CLONE given the FN. */
3891 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3892 TREE_CHAIN (fn) = clone;
3894 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3895 if (TREE_CODE (clone) == TEMPLATE_DECL)
3899 DECL_TEMPLATE_RESULT (clone)
3900 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3901 result = DECL_TEMPLATE_RESULT (clone);
3902 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3903 DECL_TI_TEMPLATE (result) = clone;
3906 note_decl_for_pch (clone);
3911 /* Produce declarations for all appropriate clones of FN. If
3912 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3913 CLASTYPE_METHOD_VEC as well. */
3916 clone_function_decl (tree fn, int update_method_vec_p)
3920 /* Avoid inappropriate cloning. */
3922 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3925 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3927 /* For each constructor, we need two variants: an in-charge version
3928 and a not-in-charge version. */
3929 clone = build_clone (fn, complete_ctor_identifier);
3930 if (update_method_vec_p)
3931 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3932 clone = build_clone (fn, base_ctor_identifier);
3933 if (update_method_vec_p)
3934 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3938 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3940 /* For each destructor, we need three variants: an in-charge
3941 version, a not-in-charge version, and an in-charge deleting
3942 version. We clone the deleting version first because that
3943 means it will go second on the TYPE_METHODS list -- and that
3944 corresponds to the correct layout order in the virtual
3947 For a non-virtual destructor, we do not build a deleting
3949 if (DECL_VIRTUAL_P (fn))
3951 clone = build_clone (fn, deleting_dtor_identifier);
3952 if (update_method_vec_p)
3953 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3955 clone = build_clone (fn, complete_dtor_identifier);
3956 if (update_method_vec_p)
3957 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3958 clone = build_clone (fn, base_dtor_identifier);
3959 if (update_method_vec_p)
3960 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3963 /* Note that this is an abstract function that is never emitted. */
3964 DECL_ABSTRACT (fn) = 1;
3967 /* DECL is an in charge constructor, which is being defined. This will
3968 have had an in class declaration, from whence clones were
3969 declared. An out-of-class definition can specify additional default
3970 arguments. As it is the clones that are involved in overload
3971 resolution, we must propagate the information from the DECL to its
3975 adjust_clone_args (tree decl)
3979 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3980 clone = TREE_CHAIN (clone))
3982 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3983 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3984 tree decl_parms, clone_parms;
3986 clone_parms = orig_clone_parms;
3988 /* Skip the 'this' parameter. */
3989 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3990 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3992 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3993 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3994 if (DECL_HAS_VTT_PARM_P (decl))
3995 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3997 clone_parms = orig_clone_parms;
3998 if (DECL_HAS_VTT_PARM_P (clone))
3999 clone_parms = TREE_CHAIN (clone_parms);
4001 for (decl_parms = orig_decl_parms; decl_parms;
4002 decl_parms = TREE_CHAIN (decl_parms),
4003 clone_parms = TREE_CHAIN (clone_parms))
4005 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
4006 TREE_TYPE (clone_parms)));
4008 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
4010 /* A default parameter has been added. Adjust the
4011 clone's parameters. */
4012 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4013 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4016 clone_parms = orig_decl_parms;
4018 if (DECL_HAS_VTT_PARM_P (clone))
4020 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
4021 TREE_VALUE (orig_clone_parms),
4023 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
4025 type = build_method_type_directly (basetype,
4026 TREE_TYPE (TREE_TYPE (clone)),
4029 type = build_exception_variant (type, exceptions);
4030 TREE_TYPE (clone) = type;
4032 clone_parms = NULL_TREE;
4036 gcc_assert (!clone_parms);
4040 /* For each of the constructors and destructors in T, create an
4041 in-charge and not-in-charge variant. */
4044 clone_constructors_and_destructors (tree t)
4048 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4050 if (!CLASSTYPE_METHOD_VEC (t))
4053 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4054 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4055 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4056 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4059 /* Returns true iff class T has a user-defined constructor other than
4060 the default constructor. */
4063 type_has_user_nondefault_constructor (tree t)
4067 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4070 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4072 tree fn = OVL_CURRENT (fns);
4073 if (!DECL_ARTIFICIAL (fn)
4074 && (TREE_CODE (fn) == TEMPLATE_DECL
4075 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
4083 /* Returns true iff FN is a user-provided function, i.e. user-declared
4084 and not defaulted at its first declaration. */
4087 user_provided_p (tree fn)
4089 if (TREE_CODE (fn) == TEMPLATE_DECL)
4092 return (!DECL_ARTIFICIAL (fn)
4093 && !(DECL_DEFAULTED_FN (fn)
4094 && DECL_INITIALIZED_IN_CLASS_P (fn)));
4097 /* Returns true iff class T has a user-provided constructor. */
4100 type_has_user_provided_constructor (tree t)
4104 if (!CLASS_TYPE_P (t))
4107 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4110 /* This can happen in error cases; avoid crashing. */
4111 if (!CLASSTYPE_METHOD_VEC (t))
4114 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4115 if (user_provided_p (OVL_CURRENT (fns)))
4121 /* Returns true iff class T has a user-provided default constructor. */
4124 type_has_user_provided_default_constructor (tree t)
4128 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4131 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4133 tree fn = OVL_CURRENT (fns);
4134 if (TREE_CODE (fn) == FUNCTION_DECL
4135 && user_provided_p (fn))
4137 args = FUNCTION_FIRST_USER_PARMTYPE (fn);
4138 while (args && TREE_PURPOSE (args))
4139 args = TREE_CHAIN (args);
4140 if (!args || args == void_list_node)
4148 /* Returns true if FN can be explicitly defaulted. */
4151 defaultable_fn_p (tree fn)
4153 if (DECL_CONSTRUCTOR_P (fn))
4155 if (FUNCTION_FIRST_USER_PARMTYPE (fn) == void_list_node)
4157 else if (copy_fn_p (fn) > 0
4158 && (TREE_CHAIN (FUNCTION_FIRST_USER_PARMTYPE (fn))
4164 else if (DECL_DESTRUCTOR_P (fn))
4166 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
4167 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
4168 return copy_fn_p (fn);
4173 /* Remove all zero-width bit-fields from T. */
4176 remove_zero_width_bit_fields (tree t)
4180 fieldsp = &TYPE_FIELDS (t);
4183 if (TREE_CODE (*fieldsp) == FIELD_DECL
4184 && DECL_C_BIT_FIELD (*fieldsp)
4185 && DECL_INITIAL (*fieldsp))
4186 *fieldsp = TREE_CHAIN (*fieldsp);
4188 fieldsp = &TREE_CHAIN (*fieldsp);
4192 /* Returns TRUE iff we need a cookie when dynamically allocating an
4193 array whose elements have the indicated class TYPE. */
4196 type_requires_array_cookie (tree type)
4199 bool has_two_argument_delete_p = false;
4201 gcc_assert (CLASS_TYPE_P (type));
4203 /* If there's a non-trivial destructor, we need a cookie. In order
4204 to iterate through the array calling the destructor for each
4205 element, we'll have to know how many elements there are. */
4206 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4209 /* If the usual deallocation function is a two-argument whose second
4210 argument is of type `size_t', then we have to pass the size of
4211 the array to the deallocation function, so we will need to store
4213 fns = lookup_fnfields (TYPE_BINFO (type),
4214 ansi_opname (VEC_DELETE_EXPR),
4216 /* If there are no `operator []' members, or the lookup is
4217 ambiguous, then we don't need a cookie. */
4218 if (!fns || fns == error_mark_node)
4220 /* Loop through all of the functions. */
4221 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4226 /* Select the current function. */
4227 fn = OVL_CURRENT (fns);
4228 /* See if this function is a one-argument delete function. If
4229 it is, then it will be the usual deallocation function. */
4230 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4231 if (second_parm == void_list_node)
4233 /* Do not consider this function if its second argument is an
4237 /* Otherwise, if we have a two-argument function and the second
4238 argument is `size_t', it will be the usual deallocation
4239 function -- unless there is one-argument function, too. */
4240 if (TREE_CHAIN (second_parm) == void_list_node
4241 && same_type_p (TREE_VALUE (second_parm), size_type_node))
4242 has_two_argument_delete_p = true;
4245 return has_two_argument_delete_p;
4248 /* Check the validity of the bases and members declared in T. Add any
4249 implicitly-generated functions (like copy-constructors and
4250 assignment operators). Compute various flag bits (like
4251 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4252 level: i.e., independently of the ABI in use. */
4255 check_bases_and_members (tree t)
4257 /* Nonzero if the implicitly generated copy constructor should take
4258 a non-const reference argument. */
4259 int cant_have_const_ctor;
4260 /* Nonzero if the implicitly generated assignment operator
4261 should take a non-const reference argument. */
4262 int no_const_asn_ref;
4264 bool saved_complex_asn_ref;
4265 bool saved_nontrivial_dtor;
4267 /* By default, we use const reference arguments and generate default
4269 cant_have_const_ctor = 0;
4270 no_const_asn_ref = 0;
4272 /* Check all the base-classes. */
4273 check_bases (t, &cant_have_const_ctor,
4276 /* Check all the method declarations. */
4279 /* Save the initial values of these flags which only indicate whether
4280 or not the class has user-provided functions. As we analyze the
4281 bases and members we can set these flags for other reasons. */
4282 saved_complex_asn_ref = TYPE_HAS_COMPLEX_ASSIGN_REF (t);
4283 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
4285 /* Check all the data member declarations. We cannot call
4286 check_field_decls until we have called check_bases check_methods,
4287 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4288 being set appropriately. */
4289 check_field_decls (t, &access_decls,
4290 &cant_have_const_ctor,
4293 /* A nearly-empty class has to be vptr-containing; a nearly empty
4294 class contains just a vptr. */
4295 if (!TYPE_CONTAINS_VPTR_P (t))
4296 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4298 /* Do some bookkeeping that will guide the generation of implicitly
4299 declared member functions. */
4300 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4301 /* We need to call a constructor for this class if it has a
4302 user-provided constructor, or if the default constructor is going
4303 to initialize the vptr. (This is not an if-and-only-if;
4304 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4305 themselves need constructing.) */
4306 TYPE_NEEDS_CONSTRUCTING (t)
4307 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t));
4310 An aggregate is an array or a class with no user-provided
4311 constructors ... and no virtual functions.
4313 Again, other conditions for being an aggregate are checked
4315 CLASSTYPE_NON_AGGREGATE (t)
4316 |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t));
4317 CLASSTYPE_NON_POD_P (t)
4318 |= (CLASSTYPE_NON_AGGREGATE (t)
4319 || saved_nontrivial_dtor || saved_complex_asn_ref);
4320 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4321 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
4323 /* If the class has no user-declared constructor, but does have
4324 non-static const or reference data members that can never be
4325 initialized, issue a warning. */
4326 if (warn_uninitialized
4327 /* Classes with user-declared constructors are presumed to
4328 initialize these members. */
4329 && !TYPE_HAS_USER_CONSTRUCTOR (t)
4330 /* Aggregates can be initialized with brace-enclosed
4332 && CLASSTYPE_NON_AGGREGATE (t))
4336 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4340 if (TREE_CODE (field) != FIELD_DECL)
4343 type = TREE_TYPE (field);
4344 if (TREE_CODE (type) == REFERENCE_TYPE)
4345 warning (OPT_Wuninitialized, "non-static reference %q+#D "
4346 "in class without a constructor", field);
4347 else if (CP_TYPE_CONST_P (type)
4348 && (!CLASS_TYPE_P (type)
4349 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type)))
4350 warning (OPT_Wuninitialized, "non-static const member %q+#D "
4351 "in class without a constructor", field);
4355 /* Synthesize any needed methods. */
4356 add_implicitly_declared_members (t,
4357 cant_have_const_ctor,
4360 /* Create the in-charge and not-in-charge variants of constructors
4362 clone_constructors_and_destructors (t);
4364 /* Process the using-declarations. */
4365 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4366 handle_using_decl (TREE_VALUE (access_decls), t);
4368 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4369 finish_struct_methods (t);
4371 /* Figure out whether or not we will need a cookie when dynamically
4372 allocating an array of this type. */
4373 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4374 = type_requires_array_cookie (t);
4377 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4378 accordingly. If a new vfield was created (because T doesn't have a
4379 primary base class), then the newly created field is returned. It
4380 is not added to the TYPE_FIELDS list; it is the caller's
4381 responsibility to do that. Accumulate declared virtual functions
4385 create_vtable_ptr (tree t, tree* virtuals_p)
4389 /* Collect the virtual functions declared in T. */
4390 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4391 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4392 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4394 tree new_virtual = make_node (TREE_LIST);
4396 BV_FN (new_virtual) = fn;
4397 BV_DELTA (new_virtual) = integer_zero_node;
4398 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4400 TREE_CHAIN (new_virtual) = *virtuals_p;
4401 *virtuals_p = new_virtual;
4404 /* If we couldn't find an appropriate base class, create a new field
4405 here. Even if there weren't any new virtual functions, we might need a
4406 new virtual function table if we're supposed to include vptrs in
4407 all classes that need them. */
4408 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4410 /* We build this decl with vtbl_ptr_type_node, which is a
4411 `vtable_entry_type*'. It might seem more precise to use
4412 `vtable_entry_type (*)[N]' where N is the number of virtual
4413 functions. However, that would require the vtable pointer in
4414 base classes to have a different type than the vtable pointer
4415 in derived classes. We could make that happen, but that
4416 still wouldn't solve all the problems. In particular, the
4417 type-based alias analysis code would decide that assignments
4418 to the base class vtable pointer can't alias assignments to
4419 the derived class vtable pointer, since they have different
4420 types. Thus, in a derived class destructor, where the base
4421 class constructor was inlined, we could generate bad code for
4422 setting up the vtable pointer.
4424 Therefore, we use one type for all vtable pointers. We still
4425 use a type-correct type; it's just doesn't indicate the array
4426 bounds. That's better than using `void*' or some such; it's
4427 cleaner, and it let's the alias analysis code know that these
4428 stores cannot alias stores to void*! */
4431 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4432 DECL_VIRTUAL_P (field) = 1;
4433 DECL_ARTIFICIAL (field) = 1;
4434 DECL_FIELD_CONTEXT (field) = t;
4435 DECL_FCONTEXT (field) = t;
4437 TYPE_VFIELD (t) = field;
4439 /* This class is non-empty. */
4440 CLASSTYPE_EMPTY_P (t) = 0;
4448 /* Fixup the inline function given by INFO now that the class is
4452 fixup_pending_inline (tree fn)
4454 if (DECL_PENDING_INLINE_INFO (fn))
4456 tree args = DECL_ARGUMENTS (fn);
4459 DECL_CONTEXT (args) = fn;
4460 args = TREE_CHAIN (args);
4465 /* Fixup the inline methods and friends in TYPE now that TYPE is
4469 fixup_inline_methods (tree type)
4471 tree method = TYPE_METHODS (type);
4472 VEC(tree,gc) *friends;
4475 if (method && TREE_CODE (method) == TREE_VEC)
4477 if (TREE_VEC_ELT (method, 1))
4478 method = TREE_VEC_ELT (method, 1);
4479 else if (TREE_VEC_ELT (method, 0))
4480 method = TREE_VEC_ELT (method, 0);
4482 method = TREE_VEC_ELT (method, 2);
4485 /* Do inline member functions. */
4486 for (; method; method = TREE_CHAIN (method))
4487 fixup_pending_inline (method);
4490 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4491 VEC_iterate (tree, friends, ix, method); ix++)
4492 fixup_pending_inline (method);
4493 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4496 /* Add OFFSET to all base types of BINFO which is a base in the
4497 hierarchy dominated by T.
4499 OFFSET, which is a type offset, is number of bytes. */
4502 propagate_binfo_offsets (tree binfo, tree offset)
4508 /* Update BINFO's offset. */
4509 BINFO_OFFSET (binfo)
4510 = convert (sizetype,
4511 size_binop (PLUS_EXPR,
4512 convert (ssizetype, BINFO_OFFSET (binfo)),
4515 /* Find the primary base class. */
4516 primary_binfo = get_primary_binfo (binfo);
4518 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4519 propagate_binfo_offsets (primary_binfo, offset);
4521 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4523 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4525 /* Don't do the primary base twice. */
4526 if (base_binfo == primary_binfo)
4529 if (BINFO_VIRTUAL_P (base_binfo))
4532 propagate_binfo_offsets (base_binfo, offset);
4536 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4537 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4538 empty subobjects of T. */
4541 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4545 bool first_vbase = true;
4548 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4551 if (!abi_version_at_least(2))
4553 /* In G++ 3.2, we incorrectly rounded the size before laying out
4554 the virtual bases. */
4555 finish_record_layout (rli, /*free_p=*/false);
4556 #ifdef STRUCTURE_SIZE_BOUNDARY
4557 /* Packed structures don't need to have minimum size. */
4558 if (! TYPE_PACKED (t))
4559 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4561 rli->offset = TYPE_SIZE_UNIT (t);
4562 rli->bitpos = bitsize_zero_node;
4563 rli->record_align = TYPE_ALIGN (t);
4566 /* Find the last field. The artificial fields created for virtual
4567 bases will go after the last extant field to date. */
4568 next_field = &TYPE_FIELDS (t);
4570 next_field = &TREE_CHAIN (*next_field);
4572 /* Go through the virtual bases, allocating space for each virtual
4573 base that is not already a primary base class. These are
4574 allocated in inheritance graph order. */
4575 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4577 if (!BINFO_VIRTUAL_P (vbase))
4580 if (!BINFO_PRIMARY_P (vbase))
4582 tree basetype = TREE_TYPE (vbase);
4584 /* This virtual base is not a primary base of any class in the
4585 hierarchy, so we have to add space for it. */
4586 next_field = build_base_field (rli, vbase,
4587 offsets, next_field);
4589 /* If the first virtual base might have been placed at a
4590 lower address, had we started from CLASSTYPE_SIZE, rather
4591 than TYPE_SIZE, issue a warning. There can be both false
4592 positives and false negatives from this warning in rare
4593 cases; to deal with all the possibilities would probably
4594 require performing both layout algorithms and comparing
4595 the results which is not particularly tractable. */
4599 (size_binop (CEIL_DIV_EXPR,
4600 round_up (CLASSTYPE_SIZE (t),
4601 CLASSTYPE_ALIGN (basetype)),
4603 BINFO_OFFSET (vbase))))
4605 "offset of virtual base %qT is not ABI-compliant and "
4606 "may change in a future version of GCC",
4609 first_vbase = false;
4614 /* Returns the offset of the byte just past the end of the base class
4618 end_of_base (tree binfo)
4622 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo)))
4623 size = TYPE_SIZE_UNIT (char_type_node);
4624 else if (is_empty_class (BINFO_TYPE (binfo)))
4625 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4626 allocate some space for it. It cannot have virtual bases, so
4627 TYPE_SIZE_UNIT is fine. */
4628 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4630 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4632 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4635 /* Returns the offset of the byte just past the end of the base class
4636 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4637 only non-virtual bases are included. */
4640 end_of_class (tree t, int include_virtuals_p)
4642 tree result = size_zero_node;
4643 VEC(tree,gc) *vbases;
4649 for (binfo = TYPE_BINFO (t), i = 0;
4650 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4652 if (!include_virtuals_p
4653 && BINFO_VIRTUAL_P (base_binfo)
4654 && (!BINFO_PRIMARY_P (base_binfo)
4655 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4658 offset = end_of_base (base_binfo);
4659 if (INT_CST_LT_UNSIGNED (result, offset))
4663 /* G++ 3.2 did not check indirect virtual bases. */
4664 if (abi_version_at_least (2) && include_virtuals_p)
4665 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4666 VEC_iterate (tree, vbases, i, base_binfo); i++)
4668 offset = end_of_base (base_binfo);
4669 if (INT_CST_LT_UNSIGNED (result, offset))
4676 /* Warn about bases of T that are inaccessible because they are
4677 ambiguous. For example:
4680 struct T : public S {};
4681 struct U : public S, public T {};
4683 Here, `(S*) new U' is not allowed because there are two `S'
4687 warn_about_ambiguous_bases (tree t)
4690 VEC(tree,gc) *vbases;
4695 /* If there are no repeated bases, nothing can be ambiguous. */
4696 if (!CLASSTYPE_REPEATED_BASE_P (t))
4699 /* Check direct bases. */
4700 for (binfo = TYPE_BINFO (t), i = 0;
4701 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4703 basetype = BINFO_TYPE (base_binfo);
4705 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4706 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4710 /* Check for ambiguous virtual bases. */
4712 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4713 VEC_iterate (tree, vbases, i, binfo); i++)
4715 basetype = BINFO_TYPE (binfo);
4717 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4718 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity",
4723 /* Compare two INTEGER_CSTs K1 and K2. */
4726 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4728 return tree_int_cst_compare ((tree) k1, (tree) k2);
4731 /* Increase the size indicated in RLI to account for empty classes
4732 that are "off the end" of the class. */
4735 include_empty_classes (record_layout_info rli)
4740 /* It might be the case that we grew the class to allocate a
4741 zero-sized base class. That won't be reflected in RLI, yet,
4742 because we are willing to overlay multiple bases at the same
4743 offset. However, now we need to make sure that RLI is big enough
4744 to reflect the entire class. */
4745 eoc = end_of_class (rli->t,
4746 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4747 rli_size = rli_size_unit_so_far (rli);
4748 if (TREE_CODE (rli_size) == INTEGER_CST
4749 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4751 if (!abi_version_at_least (2))
4752 /* In version 1 of the ABI, the size of a class that ends with
4753 a bitfield was not rounded up to a whole multiple of a
4754 byte. Because rli_size_unit_so_far returns only the number
4755 of fully allocated bytes, any extra bits were not included
4757 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4759 /* The size should have been rounded to a whole byte. */
4760 gcc_assert (tree_int_cst_equal
4761 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4763 = size_binop (PLUS_EXPR,
4765 size_binop (MULT_EXPR,
4766 convert (bitsizetype,
4767 size_binop (MINUS_EXPR,
4769 bitsize_int (BITS_PER_UNIT)));
4770 normalize_rli (rli);
4774 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4775 BINFO_OFFSETs for all of the base-classes. Position the vtable
4776 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4779 layout_class_type (tree t, tree *virtuals_p)
4781 tree non_static_data_members;
4784 record_layout_info rli;
4785 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4786 types that appear at that offset. */
4787 splay_tree empty_base_offsets;
4788 /* True if the last field layed out was a bit-field. */
4789 bool last_field_was_bitfield = false;
4790 /* The location at which the next field should be inserted. */
4792 /* T, as a base class. */
4795 /* Keep track of the first non-static data member. */
4796 non_static_data_members = TYPE_FIELDS (t);
4798 /* Start laying out the record. */
4799 rli = start_record_layout (t);
4801 /* Mark all the primary bases in the hierarchy. */
4802 determine_primary_bases (t);
4804 /* Create a pointer to our virtual function table. */
4805 vptr = create_vtable_ptr (t, virtuals_p);
4807 /* The vptr is always the first thing in the class. */
4810 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4811 TYPE_FIELDS (t) = vptr;
4812 next_field = &TREE_CHAIN (vptr);
4813 place_field (rli, vptr);
4816 next_field = &TYPE_FIELDS (t);
4818 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4819 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4821 build_base_fields (rli, empty_base_offsets, next_field);
4823 /* Layout the non-static data members. */
4824 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4829 /* We still pass things that aren't non-static data members to
4830 the back end, in case it wants to do something with them. */
4831 if (TREE_CODE (field) != FIELD_DECL)
4833 place_field (rli, field);
4834 /* If the static data member has incomplete type, keep track
4835 of it so that it can be completed later. (The handling
4836 of pending statics in finish_record_layout is
4837 insufficient; consider:
4840 struct S2 { static S1 s1; };
4842 At this point, finish_record_layout will be called, but
4843 S1 is still incomplete.) */
4844 if (TREE_CODE (field) == VAR_DECL)
4846 maybe_register_incomplete_var (field);
4847 /* The visibility of static data members is determined
4848 at their point of declaration, not their point of
4850 determine_visibility (field);
4855 type = TREE_TYPE (field);
4856 if (type == error_mark_node)
4859 padding = NULL_TREE;
4861 /* If this field is a bit-field whose width is greater than its
4862 type, then there are some special rules for allocating
4864 if (DECL_C_BIT_FIELD (field)
4865 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4869 bool was_unnamed_p = false;
4870 /* We must allocate the bits as if suitably aligned for the
4871 longest integer type that fits in this many bits. type
4872 of the field. Then, we are supposed to use the left over
4873 bits as additional padding. */
4874 for (itk = itk_char; itk != itk_none; ++itk)
4875 if (INT_CST_LT (DECL_SIZE (field),
4876 TYPE_SIZE (integer_types[itk])))
4879 /* ITK now indicates a type that is too large for the
4880 field. We have to back up by one to find the largest
4882 integer_type = integer_types[itk - 1];
4884 /* Figure out how much additional padding is required. GCC
4885 3.2 always created a padding field, even if it had zero
4887 if (!abi_version_at_least (2)
4888 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4890 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4891 /* In a union, the padding field must have the full width
4892 of the bit-field; all fields start at offset zero. */
4893 padding = DECL_SIZE (field);
4896 if (TREE_CODE (t) == UNION_TYPE)
4897 warning (OPT_Wabi, "size assigned to %qT may not be "
4898 "ABI-compliant and may change in a future "
4901 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4902 TYPE_SIZE (integer_type));
4905 #ifdef PCC_BITFIELD_TYPE_MATTERS
4906 /* An unnamed bitfield does not normally affect the
4907 alignment of the containing class on a target where
4908 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4909 make any exceptions for unnamed bitfields when the
4910 bitfields are longer than their types. Therefore, we
4911 temporarily give the field a name. */
4912 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4914 was_unnamed_p = true;
4915 DECL_NAME (field) = make_anon_name ();
4918 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4919 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4920 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4921 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4922 empty_base_offsets);
4924 DECL_NAME (field) = NULL_TREE;
4925 /* Now that layout has been performed, set the size of the
4926 field to the size of its declared type; the rest of the
4927 field is effectively invisible. */
4928 DECL_SIZE (field) = TYPE_SIZE (type);
4929 /* We must also reset the DECL_MODE of the field. */
4930 if (abi_version_at_least (2))
4931 DECL_MODE (field) = TYPE_MODE (type);
4933 && DECL_MODE (field) != TYPE_MODE (type))
4934 /* Versions of G++ before G++ 3.4 did not reset the
4937 "the offset of %qD may not be ABI-compliant and may "
4938 "change in a future version of GCC", field);
4941 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4942 empty_base_offsets);
4944 /* Remember the location of any empty classes in FIELD. */
4945 if (abi_version_at_least (2))
4946 record_subobject_offsets (TREE_TYPE (field),
4947 byte_position(field),
4949 /*is_data_member=*/true);
4951 /* If a bit-field does not immediately follow another bit-field,
4952 and yet it starts in the middle of a byte, we have failed to
4953 comply with the ABI. */
4955 && DECL_C_BIT_FIELD (field)
4956 /* The TREE_NO_WARNING flag gets set by Objective-C when
4957 laying out an Objective-C class. The ObjC ABI differs
4958 from the C++ ABI, and so we do not want a warning
4960 && !TREE_NO_WARNING (field)
4961 && !last_field_was_bitfield
4962 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4963 DECL_FIELD_BIT_OFFSET (field),
4964 bitsize_unit_node)))
4965 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
4966 "change in a future version of GCC", field);
4968 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4969 offset of the field. */
4971 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4972 byte_position (field))
4973 && contains_empty_class_p (TREE_TYPE (field)))
4974 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
4975 "classes to be placed at different locations in a "
4976 "future version of GCC", field);
4978 /* The middle end uses the type of expressions to determine the
4979 possible range of expression values. In order to optimize
4980 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
4981 must be made aware of the width of "i", via its type.
4983 Because C++ does not have integer types of arbitrary width,
4984 we must (for the purposes of the front end) convert from the
4985 type assigned here to the declared type of the bitfield
4986 whenever a bitfield expression is used as an rvalue.
4987 Similarly, when assigning a value to a bitfield, the value
4988 must be converted to the type given the bitfield here. */
4989 if (DECL_C_BIT_FIELD (field))
4991 unsigned HOST_WIDE_INT width;
4992 tree ftype = TREE_TYPE (field);
4993 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
4994 if (width != TYPE_PRECISION (ftype))
4997 = c_build_bitfield_integer_type (width,
4998 TYPE_UNSIGNED (ftype));
5000 = cp_build_qualified_type (TREE_TYPE (field),
5001 TYPE_QUALS (ftype));
5005 /* If we needed additional padding after this field, add it
5011 padding_field = build_decl (FIELD_DECL,
5014 DECL_BIT_FIELD (padding_field) = 1;
5015 DECL_SIZE (padding_field) = padding;
5016 DECL_CONTEXT (padding_field) = t;
5017 DECL_ARTIFICIAL (padding_field) = 1;
5018 DECL_IGNORED_P (padding_field) = 1;
5019 layout_nonempty_base_or_field (rli, padding_field,
5021 empty_base_offsets);
5024 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
5027 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
5029 /* Make sure that we are on a byte boundary so that the size of
5030 the class without virtual bases will always be a round number
5032 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
5033 normalize_rli (rli);
5036 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5038 if (!abi_version_at_least (2))
5039 include_empty_classes(rli);
5041 /* Delete all zero-width bit-fields from the list of fields. Now
5042 that the type is laid out they are no longer important. */
5043 remove_zero_width_bit_fields (t);
5045 /* Create the version of T used for virtual bases. We do not use
5046 make_class_type for this version; this is an artificial type. For
5047 a POD type, we just reuse T. */
5048 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
5050 base_t = make_node (TREE_CODE (t));
5052 /* Set the size and alignment for the new type. In G++ 3.2, all
5053 empty classes were considered to have size zero when used as
5055 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
5057 TYPE_SIZE (base_t) = bitsize_zero_node;
5058 TYPE_SIZE_UNIT (base_t) = size_zero_node;
5059 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
5061 "layout of classes derived from empty class %qT "
5062 "may change in a future version of GCC",
5069 /* If the ABI version is not at least two, and the last
5070 field was a bit-field, RLI may not be on a byte
5071 boundary. In particular, rli_size_unit_so_far might
5072 indicate the last complete byte, while rli_size_so_far
5073 indicates the total number of bits used. Therefore,
5074 rli_size_so_far, rather than rli_size_unit_so_far, is
5075 used to compute TYPE_SIZE_UNIT. */
5076 eoc = end_of_class (t, /*include_virtuals_p=*/0);
5077 TYPE_SIZE_UNIT (base_t)
5078 = size_binop (MAX_EXPR,
5080 size_binop (CEIL_DIV_EXPR,
5081 rli_size_so_far (rli),
5082 bitsize_int (BITS_PER_UNIT))),
5085 = size_binop (MAX_EXPR,
5086 rli_size_so_far (rli),
5087 size_binop (MULT_EXPR,
5088 convert (bitsizetype, eoc),
5089 bitsize_int (BITS_PER_UNIT)));
5091 TYPE_ALIGN (base_t) = rli->record_align;
5092 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
5094 /* Copy the fields from T. */
5095 next_field = &TYPE_FIELDS (base_t);
5096 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5097 if (TREE_CODE (field) == FIELD_DECL)
5099 *next_field = build_decl (FIELD_DECL,
5102 DECL_CONTEXT (*next_field) = base_t;
5103 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
5104 DECL_FIELD_BIT_OFFSET (*next_field)
5105 = DECL_FIELD_BIT_OFFSET (field);
5106 DECL_SIZE (*next_field) = DECL_SIZE (field);
5107 DECL_MODE (*next_field) = DECL_MODE (field);
5108 next_field = &TREE_CHAIN (*next_field);
5111 /* Record the base version of the type. */
5112 CLASSTYPE_AS_BASE (t) = base_t;
5113 TYPE_CONTEXT (base_t) = t;
5116 CLASSTYPE_AS_BASE (t) = t;
5118 /* Every empty class contains an empty class. */
5119 if (CLASSTYPE_EMPTY_P (t))
5120 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
5122 /* Set the TYPE_DECL for this type to contain the right
5123 value for DECL_OFFSET, so that we can use it as part
5124 of a COMPONENT_REF for multiple inheritance. */
5125 layout_decl (TYPE_MAIN_DECL (t), 0);
5127 /* Now fix up any virtual base class types that we left lying
5128 around. We must get these done before we try to lay out the
5129 virtual function table. As a side-effect, this will remove the
5130 base subobject fields. */
5131 layout_virtual_bases (rli, empty_base_offsets);
5133 /* Make sure that empty classes are reflected in RLI at this
5135 include_empty_classes(rli);
5137 /* Make sure not to create any structures with zero size. */
5138 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
5140 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
5142 /* Let the back end lay out the type. */
5143 finish_record_layout (rli, /*free_p=*/true);
5145 /* Warn about bases that can't be talked about due to ambiguity. */
5146 warn_about_ambiguous_bases (t);
5148 /* Now that we're done with layout, give the base fields the real types. */
5149 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5150 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
5151 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
5154 splay_tree_delete (empty_base_offsets);
5156 if (CLASSTYPE_EMPTY_P (t)
5157 && tree_int_cst_lt (sizeof_biggest_empty_class,
5158 TYPE_SIZE_UNIT (t)))
5159 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
5162 /* Determine the "key method" for the class type indicated by TYPE,
5163 and set CLASSTYPE_KEY_METHOD accordingly. */
5166 determine_key_method (tree type)
5170 if (TYPE_FOR_JAVA (type)
5171 || processing_template_decl
5172 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
5173 || CLASSTYPE_INTERFACE_KNOWN (type))
5176 /* The key method is the first non-pure virtual function that is not
5177 inline at the point of class definition. On some targets the
5178 key function may not be inline; those targets should not call
5179 this function until the end of the translation unit. */
5180 for (method = TYPE_METHODS (type); method != NULL_TREE;
5181 method = TREE_CHAIN (method))
5182 if (DECL_VINDEX (method) != NULL_TREE
5183 && ! DECL_DECLARED_INLINE_P (method)
5184 && ! DECL_PURE_VIRTUAL_P (method))
5186 CLASSTYPE_KEY_METHOD (type) = method;
5193 /* Perform processing required when the definition of T (a class type)
5197 finish_struct_1 (tree t)
5200 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5201 tree virtuals = NULL_TREE;
5204 if (COMPLETE_TYPE_P (t))
5206 gcc_assert (MAYBE_CLASS_TYPE_P (t));
5207 error ("redefinition of %q#T", t);
5212 /* If this type was previously laid out as a forward reference,
5213 make sure we lay it out again. */
5214 TYPE_SIZE (t) = NULL_TREE;
5215 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
5217 fixup_inline_methods (t);
5219 /* Make assumptions about the class; we'll reset the flags if
5221 CLASSTYPE_EMPTY_P (t) = 1;
5222 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
5223 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
5225 /* Do end-of-class semantic processing: checking the validity of the
5226 bases and members and add implicitly generated methods. */
5227 check_bases_and_members (t);
5229 /* Find the key method. */
5230 if (TYPE_CONTAINS_VPTR_P (t))
5232 /* The Itanium C++ ABI permits the key method to be chosen when
5233 the class is defined -- even though the key method so
5234 selected may later turn out to be an inline function. On
5235 some systems (such as ARM Symbian OS) the key method cannot
5236 be determined until the end of the translation unit. On such
5237 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5238 will cause the class to be added to KEYED_CLASSES. Then, in
5239 finish_file we will determine the key method. */
5240 if (targetm.cxx.key_method_may_be_inline ())
5241 determine_key_method (t);
5243 /* If a polymorphic class has no key method, we may emit the vtable
5244 in every translation unit where the class definition appears. */
5245 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
5246 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
5249 /* Layout the class itself. */
5250 layout_class_type (t, &virtuals);
5251 if (CLASSTYPE_AS_BASE (t) != t)
5252 /* We use the base type for trivial assignments, and hence it
5254 compute_record_mode (CLASSTYPE_AS_BASE (t));
5256 virtuals = modify_all_vtables (t, nreverse (virtuals));
5258 /* If necessary, create the primary vtable for this class. */
5259 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
5261 /* We must enter these virtuals into the table. */
5262 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5263 build_primary_vtable (NULL_TREE, t);
5264 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
5265 /* Here we know enough to change the type of our virtual
5266 function table, but we will wait until later this function. */
5267 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
5270 if (TYPE_CONTAINS_VPTR_P (t))
5275 if (BINFO_VTABLE (TYPE_BINFO (t)))
5276 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5277 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5278 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5280 /* Add entries for virtual functions introduced by this class. */
5281 BINFO_VIRTUALS (TYPE_BINFO (t))
5282 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5284 /* Set DECL_VINDEX for all functions declared in this class. */
5285 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5287 fn = TREE_CHAIN (fn),
5288 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5289 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5291 tree fndecl = BV_FN (fn);
5293 if (DECL_THUNK_P (fndecl))
5294 /* A thunk. We should never be calling this entry directly
5295 from this vtable -- we'd use the entry for the non
5296 thunk base function. */
5297 DECL_VINDEX (fndecl) = NULL_TREE;
5298 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5299 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5303 finish_struct_bits (t);
5305 /* Complete the rtl for any static member objects of the type we're
5307 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5308 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5309 && TREE_TYPE (x) != error_mark_node
5310 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5311 DECL_MODE (x) = TYPE_MODE (t);
5313 /* Done with FIELDS...now decide whether to sort these for
5314 faster lookups later.
5316 We use a small number because most searches fail (succeeding
5317 ultimately as the search bores through the inheritance
5318 hierarchy), and we want this failure to occur quickly. */
5320 n_fields = count_fields (TYPE_FIELDS (t));
5323 struct sorted_fields_type *field_vec = GGC_NEWVAR
5324 (struct sorted_fields_type,
5325 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5326 field_vec->len = n_fields;
5327 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5328 qsort (field_vec->elts, n_fields, sizeof (tree),
5330 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5331 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5332 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5335 /* Complain if one of the field types requires lower visibility. */
5336 constrain_class_visibility (t);
5338 /* Make the rtl for any new vtables we have created, and unmark
5339 the base types we marked. */
5342 /* Build the VTT for T. */
5345 /* This warning does not make sense for Java classes, since they
5346 cannot have destructors. */
5347 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5351 dtor = CLASSTYPE_DESTRUCTORS (t);
5352 if (/* An implicitly declared destructor is always public. And,
5353 if it were virtual, we would have created it by now. */
5355 || (!DECL_VINDEX (dtor)
5356 && (/* public non-virtual */
5357 (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
5358 || (/* non-public non-virtual with friends */
5359 (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
5360 && (CLASSTYPE_FRIEND_CLASSES (t)
5361 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
5362 warning (OPT_Wnon_virtual_dtor,
5363 "%q#T has virtual functions and accessible"
5364 " non-virtual destructor", t);
5369 if (warn_overloaded_virtual)
5372 /* Class layout, assignment of virtual table slots, etc., is now
5373 complete. Give the back end a chance to tweak the visibility of
5374 the class or perform any other required target modifications. */
5375 targetm.cxx.adjust_class_at_definition (t);
5377 maybe_suppress_debug_info (t);
5379 dump_class_hierarchy (t);
5381 /* Finish debugging output for this type. */
5382 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5385 /* When T was built up, the member declarations were added in reverse
5386 order. Rearrange them to declaration order. */
5389 unreverse_member_declarations (tree t)
5395 /* The following lists are all in reverse order. Put them in
5396 declaration order now. */
5397 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5398 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5400 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5401 reverse order, so we can't just use nreverse. */
5403 for (x = TYPE_FIELDS (t);
5404 x && TREE_CODE (x) != TYPE_DECL;
5407 next = TREE_CHAIN (x);
5408 TREE_CHAIN (x) = prev;
5413 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5415 TYPE_FIELDS (t) = prev;
5420 finish_struct (tree t, tree attributes)
5422 location_t saved_loc = input_location;
5424 /* Now that we've got all the field declarations, reverse everything
5426 unreverse_member_declarations (t);
5428 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5430 /* Nadger the current location so that diagnostics point to the start of
5431 the struct, not the end. */
5432 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5434 if (processing_template_decl)
5438 finish_struct_methods (t);
5439 TYPE_SIZE (t) = bitsize_zero_node;
5440 TYPE_SIZE_UNIT (t) = size_zero_node;
5442 /* We need to emit an error message if this type was used as a parameter
5443 and it is an abstract type, even if it is a template. We construct
5444 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5445 account and we call complete_vars with this type, which will check
5446 the PARM_DECLS. Note that while the type is being defined,
5447 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5448 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5449 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5450 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5451 if (DECL_PURE_VIRTUAL_P (x))
5452 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5456 finish_struct_1 (t);
5458 input_location = saved_loc;
5460 TYPE_BEING_DEFINED (t) = 0;
5462 if (current_class_type)
5465 error ("trying to finish struct, but kicked out due to previous parse errors");
5467 if (processing_template_decl && at_function_scope_p ())
5468 add_stmt (build_min (TAG_DEFN, t));
5473 /* Return the dynamic type of INSTANCE, if known.
5474 Used to determine whether the virtual function table is needed
5477 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5478 of our knowledge of its type. *NONNULL should be initialized
5479 before this function is called. */
5482 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp)
5484 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5486 switch (TREE_CODE (instance))
5489 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5492 return RECUR (TREE_OPERAND (instance, 0));
5495 /* This is a call to a constructor, hence it's never zero. */
5496 if (TREE_HAS_CONSTRUCTOR (instance))
5500 return TREE_TYPE (instance);
5505 /* This is a call to a constructor, hence it's never zero. */
5506 if (TREE_HAS_CONSTRUCTOR (instance))
5510 return TREE_TYPE (instance);
5512 return RECUR (TREE_OPERAND (instance, 0));
5514 case POINTER_PLUS_EXPR:
5517 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5518 return RECUR (TREE_OPERAND (instance, 0));
5519 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5520 /* Propagate nonnull. */
5521 return RECUR (TREE_OPERAND (instance, 0));
5526 return RECUR (TREE_OPERAND (instance, 0));
5529 instance = TREE_OPERAND (instance, 0);
5532 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5533 with a real object -- given &p->f, p can still be null. */
5534 tree t = get_base_address (instance);
5535 /* ??? Probably should check DECL_WEAK here. */
5536 if (t && DECL_P (t))
5539 return RECUR (instance);
5542 /* If this component is really a base class reference, then the field
5543 itself isn't definitive. */
5544 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5545 return RECUR (TREE_OPERAND (instance, 0));
5546 return RECUR (TREE_OPERAND (instance, 1));
5550 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5551 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
5555 return TREE_TYPE (TREE_TYPE (instance));
5557 /* fall through... */
5561 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance)))
5565 return TREE_TYPE (instance);
5567 else if (instance == current_class_ptr)
5572 /* if we're in a ctor or dtor, we know our type. */
5573 if (DECL_LANG_SPECIFIC (current_function_decl)
5574 && (DECL_CONSTRUCTOR_P (current_function_decl)
5575 || DECL_DESTRUCTOR_P (current_function_decl)))
5579 return TREE_TYPE (TREE_TYPE (instance));
5582 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5584 /* We only need one hash table because it is always left empty. */
5587 ht = htab_create (37,
5592 /* Reference variables should be references to objects. */
5596 /* Enter the INSTANCE in a table to prevent recursion; a
5597 variable's initializer may refer to the variable
5599 if (TREE_CODE (instance) == VAR_DECL
5600 && DECL_INITIAL (instance)
5601 && !htab_find (ht, instance))
5606 slot = htab_find_slot (ht, instance, INSERT);
5608 type = RECUR (DECL_INITIAL (instance));
5609 htab_remove_elt (ht, instance);
5622 /* Return nonzero if the dynamic type of INSTANCE is known, and
5623 equivalent to the static type. We also handle the case where
5624 INSTANCE is really a pointer. Return negative if this is a
5625 ctor/dtor. There the dynamic type is known, but this might not be
5626 the most derived base of the original object, and hence virtual
5627 bases may not be layed out according to this type.
5629 Used to determine whether the virtual function table is needed
5632 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5633 of our knowledge of its type. *NONNULL should be initialized
5634 before this function is called. */
5637 resolves_to_fixed_type_p (tree instance, int* nonnull)
5639 tree t = TREE_TYPE (instance);
5641 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5642 if (fixed == NULL_TREE)
5644 if (POINTER_TYPE_P (t))
5646 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5648 return cdtorp ? -1 : 1;
5653 init_class_processing (void)
5655 current_class_depth = 0;
5656 current_class_stack_size = 10;
5658 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5659 local_classes = VEC_alloc (tree, gc, 8);
5660 sizeof_biggest_empty_class = size_zero_node;
5662 ridpointers[(int) RID_PUBLIC] = access_public_node;
5663 ridpointers[(int) RID_PRIVATE] = access_private_node;
5664 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5667 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5670 restore_class_cache (void)
5674 /* We are re-entering the same class we just left, so we don't
5675 have to search the whole inheritance matrix to find all the
5676 decls to bind again. Instead, we install the cached
5677 class_shadowed list and walk through it binding names. */
5678 push_binding_level (previous_class_level);
5679 class_binding_level = previous_class_level;
5680 /* Restore IDENTIFIER_TYPE_VALUE. */
5681 for (type = class_binding_level->type_shadowed;
5683 type = TREE_CHAIN (type))
5684 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5687 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5688 appropriate for TYPE.
5690 So that we may avoid calls to lookup_name, we cache the _TYPE
5691 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5693 For multiple inheritance, we perform a two-pass depth-first search
5694 of the type lattice. */
5697 pushclass (tree type)
5699 class_stack_node_t csn;
5701 type = TYPE_MAIN_VARIANT (type);
5703 /* Make sure there is enough room for the new entry on the stack. */
5704 if (current_class_depth + 1 >= current_class_stack_size)
5706 current_class_stack_size *= 2;
5708 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5709 current_class_stack_size);
5712 /* Insert a new entry on the class stack. */
5713 csn = current_class_stack + current_class_depth;
5714 csn->name = current_class_name;
5715 csn->type = current_class_type;
5716 csn->access = current_access_specifier;
5717 csn->names_used = 0;
5719 current_class_depth++;
5721 /* Now set up the new type. */
5722 current_class_name = TYPE_NAME (type);
5723 if (TREE_CODE (current_class_name) == TYPE_DECL)
5724 current_class_name = DECL_NAME (current_class_name);
5725 current_class_type = type;
5727 /* By default, things in classes are private, while things in
5728 structures or unions are public. */
5729 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5730 ? access_private_node
5731 : access_public_node);
5733 if (previous_class_level
5734 && type != previous_class_level->this_entity
5735 && current_class_depth == 1)
5737 /* Forcibly remove any old class remnants. */
5738 invalidate_class_lookup_cache ();
5741 if (!previous_class_level
5742 || type != previous_class_level->this_entity
5743 || current_class_depth > 1)
5746 restore_class_cache ();
5749 /* When we exit a toplevel class scope, we save its binding level so
5750 that we can restore it quickly. Here, we've entered some other
5751 class, so we must invalidate our cache. */
5754 invalidate_class_lookup_cache (void)
5756 previous_class_level = NULL;
5759 /* Get out of the current class scope. If we were in a class scope
5760 previously, that is the one popped to. */
5767 current_class_depth--;
5768 current_class_name = current_class_stack[current_class_depth].name;
5769 current_class_type = current_class_stack[current_class_depth].type;
5770 current_access_specifier = current_class_stack[current_class_depth].access;
5771 if (current_class_stack[current_class_depth].names_used)
5772 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5775 /* Mark the top of the class stack as hidden. */
5778 push_class_stack (void)
5780 if (current_class_depth)
5781 ++current_class_stack[current_class_depth - 1].hidden;
5784 /* Mark the top of the class stack as un-hidden. */
5787 pop_class_stack (void)
5789 if (current_class_depth)
5790 --current_class_stack[current_class_depth - 1].hidden;
5793 /* Returns 1 if the class type currently being defined is either T or
5794 a nested type of T. */
5797 currently_open_class (tree t)
5801 if (!CLASS_TYPE_P (t))
5804 /* We start looking from 1 because entry 0 is from global scope,
5806 for (i = current_class_depth; i > 0; --i)
5809 if (i == current_class_depth)
5810 c = current_class_type;
5813 if (current_class_stack[i].hidden)
5815 c = current_class_stack[i].type;
5819 if (same_type_p (c, t))
5825 /* If either current_class_type or one of its enclosing classes are derived
5826 from T, return the appropriate type. Used to determine how we found
5827 something via unqualified lookup. */
5830 currently_open_derived_class (tree t)
5834 /* The bases of a dependent type are unknown. */
5835 if (dependent_type_p (t))
5838 if (!current_class_type)
5841 if (DERIVED_FROM_P (t, current_class_type))
5842 return current_class_type;
5844 for (i = current_class_depth - 1; i > 0; --i)
5846 if (current_class_stack[i].hidden)
5848 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5849 return current_class_stack[i].type;
5855 /* When entering a class scope, all enclosing class scopes' names with
5856 static meaning (static variables, static functions, types and
5857 enumerators) have to be visible. This recursive function calls
5858 pushclass for all enclosing class contexts until global or a local
5859 scope is reached. TYPE is the enclosed class. */
5862 push_nested_class (tree type)
5864 /* A namespace might be passed in error cases, like A::B:C. */
5865 if (type == NULL_TREE
5866 || !CLASS_TYPE_P (type))
5869 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type)));
5874 /* Undoes a push_nested_class call. */
5877 pop_nested_class (void)
5879 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5882 if (context && CLASS_TYPE_P (context))
5883 pop_nested_class ();
5886 /* Returns the number of extern "LANG" blocks we are nested within. */
5889 current_lang_depth (void)
5891 return VEC_length (tree, current_lang_base);
5894 /* Set global variables CURRENT_LANG_NAME to appropriate value
5895 so that behavior of name-mangling machinery is correct. */
5898 push_lang_context (tree name)
5900 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5902 if (name == lang_name_cplusplus)
5904 current_lang_name = name;
5906 else if (name == lang_name_java)
5908 current_lang_name = name;
5909 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5910 (See record_builtin_java_type in decl.c.) However, that causes
5911 incorrect debug entries if these types are actually used.
5912 So we re-enable debug output after extern "Java". */
5913 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5914 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5915 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5916 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5917 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5918 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5919 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5920 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5922 else if (name == lang_name_c)
5924 current_lang_name = name;
5927 error ("language string %<\"%E\"%> not recognized", name);
5930 /* Get out of the current language scope. */
5933 pop_lang_context (void)
5935 current_lang_name = VEC_pop (tree, current_lang_base);
5938 /* Type instantiation routines. */
5940 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5941 matches the TARGET_TYPE. If there is no satisfactory match, return
5942 error_mark_node, and issue an error & warning messages under
5943 control of FLAGS. Permit pointers to member function if FLAGS
5944 permits. If TEMPLATE_ONLY, the name of the overloaded function was
5945 a template-id, and EXPLICIT_TARGS are the explicitly provided
5948 If OVERLOAD is for one or more member functions, then ACCESS_PATH
5949 is the base path used to reference those member functions. If
5950 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
5951 resolved to a member function, access checks will be performed and
5952 errors issued if appropriate. */
5955 resolve_address_of_overloaded_function (tree target_type,
5957 tsubst_flags_t flags,
5959 tree explicit_targs,
5962 /* Here's what the standard says:
5966 If the name is a function template, template argument deduction
5967 is done, and if the argument deduction succeeds, the deduced
5968 arguments are used to generate a single template function, which
5969 is added to the set of overloaded functions considered.
5971 Non-member functions and static member functions match targets of
5972 type "pointer-to-function" or "reference-to-function." Nonstatic
5973 member functions match targets of type "pointer-to-member
5974 function;" the function type of the pointer to member is used to
5975 select the member function from the set of overloaded member
5976 functions. If a nonstatic member function is selected, the
5977 reference to the overloaded function name is required to have the
5978 form of a pointer to member as described in 5.3.1.
5980 If more than one function is selected, any template functions in
5981 the set are eliminated if the set also contains a non-template
5982 function, and any given template function is eliminated if the
5983 set contains a second template function that is more specialized
5984 than the first according to the partial ordering rules 14.5.5.2.
5985 After such eliminations, if any, there shall remain exactly one
5986 selected function. */
5989 int is_reference = 0;
5990 /* We store the matches in a TREE_LIST rooted here. The functions
5991 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5992 interoperability with most_specialized_instantiation. */
5993 tree matches = NULL_TREE;
5996 /* By the time we get here, we should be seeing only real
5997 pointer-to-member types, not the internal POINTER_TYPE to
5998 METHOD_TYPE representation. */
5999 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
6000 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
6002 gcc_assert (is_overloaded_fn (overload));
6004 /* Check that the TARGET_TYPE is reasonable. */
6005 if (TYPE_PTRFN_P (target_type))
6007 else if (TYPE_PTRMEMFUNC_P (target_type))
6008 /* This is OK, too. */
6010 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
6012 /* This is OK, too. This comes from a conversion to reference
6014 target_type = build_reference_type (target_type);
6019 if (flags & tf_error)
6020 error ("cannot resolve overloaded function %qD based on"
6021 " conversion to type %qT",
6022 DECL_NAME (OVL_FUNCTION (overload)), target_type);
6023 return error_mark_node;
6026 /* If we can find a non-template function that matches, we can just
6027 use it. There's no point in generating template instantiations
6028 if we're just going to throw them out anyhow. But, of course, we
6029 can only do this when we don't *need* a template function. */
6034 for (fns = overload; fns; fns = OVL_NEXT (fns))
6036 tree fn = OVL_CURRENT (fns);
6039 if (TREE_CODE (fn) == TEMPLATE_DECL)
6040 /* We're not looking for templates just yet. */
6043 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6045 /* We're looking for a non-static member, and this isn't
6046 one, or vice versa. */
6049 /* Ignore functions which haven't been explicitly
6051 if (DECL_ANTICIPATED (fn))
6054 /* See if there's a match. */
6055 fntype = TREE_TYPE (fn);
6057 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
6058 else if (!is_reference)
6059 fntype = build_pointer_type (fntype);
6061 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
6062 matches = tree_cons (fn, NULL_TREE, matches);
6066 /* Now, if we've already got a match (or matches), there's no need
6067 to proceed to the template functions. But, if we don't have a
6068 match we need to look at them, too. */
6071 tree target_fn_type;
6072 tree target_arg_types;
6073 tree target_ret_type;
6076 unsigned int nargs, ia;
6081 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
6083 target_fn_type = TREE_TYPE (target_type);
6084 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
6085 target_ret_type = TREE_TYPE (target_fn_type);
6087 /* Never do unification on the 'this' parameter. */
6088 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
6089 target_arg_types = TREE_CHAIN (target_arg_types);
6091 nargs = list_length (target_arg_types);
6092 args = XALLOCAVEC (tree, nargs);
6093 for (arg = target_arg_types, ia = 0;
6094 arg != NULL_TREE && arg != void_list_node;
6095 arg = TREE_CHAIN (arg), ++ia)
6096 args[ia] = TREE_VALUE (arg);
6099 for (fns = overload; fns; fns = OVL_NEXT (fns))
6101 tree fn = OVL_CURRENT (fns);
6103 tree instantiation_type;
6106 if (TREE_CODE (fn) != TEMPLATE_DECL)
6107 /* We're only looking for templates. */
6110 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6112 /* We're not looking for a non-static member, and this is
6113 one, or vice versa. */
6116 /* Try to do argument deduction. */
6117 targs = make_tree_vec (DECL_NTPARMS (fn));
6118 if (fn_type_unification (fn, explicit_targs, targs, args, nargs,
6119 target_ret_type, DEDUCE_EXACT,
6121 /* Argument deduction failed. */
6124 /* Instantiate the template. */
6125 instantiation = instantiate_template (fn, targs, flags);
6126 if (instantiation == error_mark_node)
6127 /* Instantiation failed. */
6130 /* See if there's a match. */
6131 instantiation_type = TREE_TYPE (instantiation);
6133 instantiation_type =
6134 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
6135 else if (!is_reference)
6136 instantiation_type = build_pointer_type (instantiation_type);
6137 if (can_convert_arg (target_type, instantiation_type, instantiation,
6139 matches = tree_cons (instantiation, fn, matches);
6142 /* Now, remove all but the most specialized of the matches. */
6145 tree match = most_specialized_instantiation (matches);
6147 if (match != error_mark_node)
6148 matches = tree_cons (TREE_PURPOSE (match),
6154 /* Now we should have exactly one function in MATCHES. */
6155 if (matches == NULL_TREE)
6157 /* There were *no* matches. */
6158 if (flags & tf_error)
6160 error ("no matches converting function %qD to type %q#T",
6161 DECL_NAME (OVL_CURRENT (overload)),
6164 /* print_candidates expects a chain with the functions in
6165 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6166 so why be clever?). */
6167 for (; overload; overload = OVL_NEXT (overload))
6168 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
6171 print_candidates (matches);
6173 return error_mark_node;
6175 else if (TREE_CHAIN (matches))
6177 /* There were too many matches. First check if they're all
6178 the same function. */
6181 fn = TREE_PURPOSE (matches);
6182 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match))
6183 if (!decls_match (fn, TREE_PURPOSE (matches)))
6188 if (flags & tf_error)
6190 error ("converting overloaded function %qD to type %q#T is ambiguous",
6191 DECL_NAME (OVL_FUNCTION (overload)),
6194 /* Since print_candidates expects the functions in the
6195 TREE_VALUE slot, we flip them here. */
6196 for (match = matches; match; match = TREE_CHAIN (match))
6197 TREE_VALUE (match) = TREE_PURPOSE (match);
6199 print_candidates (matches);
6202 return error_mark_node;
6206 /* Good, exactly one match. Now, convert it to the correct type. */
6207 fn = TREE_PURPOSE (matches);
6209 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
6210 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
6212 static int explained;
6214 if (!(flags & tf_error))
6215 return error_mark_node;
6217 permerror (input_location, "assuming pointer to member %qD", fn);
6220 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn);
6225 /* If we're doing overload resolution purely for the purpose of
6226 determining conversion sequences, we should not consider the
6227 function used. If this conversion sequence is selected, the
6228 function will be marked as used at this point. */
6229 if (!(flags & tf_conv))
6231 /* Make =delete work with SFINAE. */
6232 if (DECL_DELETED_FN (fn) && !(flags & tf_error))
6233 return error_mark_node;
6238 /* We could not check access to member functions when this
6239 expression was originally created since we did not know at that
6240 time to which function the expression referred. */
6241 if (!(flags & tf_no_access_control)
6242 && DECL_FUNCTION_MEMBER_P (fn))
6244 gcc_assert (access_path);
6245 perform_or_defer_access_check (access_path, fn, fn);
6248 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
6249 return cp_build_unary_op (ADDR_EXPR, fn, 0, flags);
6252 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6253 will mark the function as addressed, but here we must do it
6255 cxx_mark_addressable (fn);
6261 /* This function will instantiate the type of the expression given in
6262 RHS to match the type of LHSTYPE. If errors exist, then return
6263 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6264 we complain on errors. If we are not complaining, never modify rhs,
6265 as overload resolution wants to try many possible instantiations, in
6266 the hope that at least one will work.
6268 For non-recursive calls, LHSTYPE should be a function, pointer to
6269 function, or a pointer to member function. */
6272 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
6274 tsubst_flags_t flags_in = flags;
6275 tree access_path = NULL_TREE;
6277 flags &= ~tf_ptrmem_ok;
6279 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
6281 if (flags & tf_error)
6282 error ("not enough type information");
6283 return error_mark_node;
6286 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
6288 if (same_type_p (lhstype, TREE_TYPE (rhs)))
6290 if (flag_ms_extensions
6291 && TYPE_PTRMEMFUNC_P (lhstype)
6292 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
6293 /* Microsoft allows `A::f' to be resolved to a
6294 pointer-to-member. */
6298 if (flags & tf_error)
6299 error ("argument of type %qT does not match %qT",
6300 TREE_TYPE (rhs), lhstype);
6301 return error_mark_node;
6305 if (TREE_CODE (rhs) == BASELINK)
6307 access_path = BASELINK_ACCESS_BINFO (rhs);
6308 rhs = BASELINK_FUNCTIONS (rhs);
6311 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6312 deduce any type information. */
6313 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
6315 if (flags & tf_error)
6316 error ("not enough type information");
6317 return error_mark_node;
6320 /* There only a few kinds of expressions that may have a type
6321 dependent on overload resolution. */
6322 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
6323 || TREE_CODE (rhs) == COMPONENT_REF
6324 || really_overloaded_fn (rhs)
6325 || (flag_ms_extensions && TREE_CODE (rhs) == FUNCTION_DECL));
6327 /* This should really only be used when attempting to distinguish
6328 what sort of a pointer to function we have. For now, any
6329 arithmetic operation which is not supported on pointers
6330 is rejected as an error. */
6332 switch (TREE_CODE (rhs))
6336 tree member = TREE_OPERAND (rhs, 1);
6338 member = instantiate_type (lhstype, member, flags);
6339 if (member != error_mark_node
6340 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6341 /* Do not lose object's side effects. */
6342 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6343 TREE_OPERAND (rhs, 0), member);
6348 rhs = TREE_OPERAND (rhs, 1);
6349 if (BASELINK_P (rhs))
6350 return instantiate_type (lhstype, rhs, flags_in);
6352 /* This can happen if we are forming a pointer-to-member for a
6354 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6358 case TEMPLATE_ID_EXPR:
6360 tree fns = TREE_OPERAND (rhs, 0);
6361 tree args = TREE_OPERAND (rhs, 1);
6364 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6365 /*template_only=*/true,
6372 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6373 /*template_only=*/false,
6374 /*explicit_targs=*/NULL_TREE,
6379 if (PTRMEM_OK_P (rhs))
6380 flags |= tf_ptrmem_ok;
6382 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6386 return error_mark_node;
6391 return error_mark_node;
6394 /* Return the name of the virtual function pointer field
6395 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6396 this may have to look back through base types to find the
6397 ultimate field name. (For single inheritance, these could
6398 all be the same name. Who knows for multiple inheritance). */
6401 get_vfield_name (tree type)
6403 tree binfo, base_binfo;
6406 for (binfo = TYPE_BINFO (type);
6407 BINFO_N_BASE_BINFOS (binfo);
6410 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6412 if (BINFO_VIRTUAL_P (base_binfo)
6413 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6417 type = BINFO_TYPE (binfo);
6418 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
6419 + TYPE_NAME_LENGTH (type) + 2);
6420 sprintf (buf, VFIELD_NAME_FORMAT,
6421 IDENTIFIER_POINTER (constructor_name (type)));
6422 return get_identifier (buf);
6426 print_class_statistics (void)
6428 #ifdef GATHER_STATISTICS
6429 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6430 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6433 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6434 n_vtables, n_vtable_searches);
6435 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6436 n_vtable_entries, n_vtable_elems);
6441 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6442 according to [class]:
6443 The class-name is also inserted
6444 into the scope of the class itself. For purposes of access checking,
6445 the inserted class name is treated as if it were a public member name. */
6448 build_self_reference (void)
6450 tree name = constructor_name (current_class_type);
6451 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6454 DECL_NONLOCAL (value) = 1;
6455 DECL_CONTEXT (value) = current_class_type;
6456 DECL_ARTIFICIAL (value) = 1;
6457 SET_DECL_SELF_REFERENCE_P (value);
6459 if (processing_template_decl)
6460 value = push_template_decl (value);
6462 saved_cas = current_access_specifier;
6463 current_access_specifier = access_public_node;
6464 finish_member_declaration (value);
6465 current_access_specifier = saved_cas;
6468 /* Returns 1 if TYPE contains only padding bytes. */
6471 is_empty_class (tree type)
6473 if (type == error_mark_node)
6476 if (! CLASS_TYPE_P (type))
6479 /* In G++ 3.2, whether or not a class was empty was determined by
6480 looking at its size. */
6481 if (abi_version_at_least (2))
6482 return CLASSTYPE_EMPTY_P (type);
6484 return integer_zerop (CLASSTYPE_SIZE (type));
6487 /* Returns true if TYPE contains an empty class. */
6490 contains_empty_class_p (tree type)
6492 if (is_empty_class (type))
6494 if (CLASS_TYPE_P (type))
6501 for (binfo = TYPE_BINFO (type), i = 0;
6502 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6503 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6505 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6506 if (TREE_CODE (field) == FIELD_DECL
6507 && !DECL_ARTIFICIAL (field)
6508 && is_empty_class (TREE_TYPE (field)))
6511 else if (TREE_CODE (type) == ARRAY_TYPE)
6512 return contains_empty_class_p (TREE_TYPE (type));
6516 /* Returns true if TYPE contains no actual data, just various
6517 possible combinations of empty classes. */
6520 is_really_empty_class (tree type)
6522 if (is_empty_class (type))
6524 if (CLASS_TYPE_P (type))
6531 for (binfo = TYPE_BINFO (type), i = 0;
6532 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6533 if (!is_really_empty_class (BINFO_TYPE (base_binfo)))
6535 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6536 if (TREE_CODE (field) == FIELD_DECL
6537 && !DECL_ARTIFICIAL (field)
6538 && !is_really_empty_class (TREE_TYPE (field)))
6542 else if (TREE_CODE (type) == ARRAY_TYPE)
6543 return is_really_empty_class (TREE_TYPE (type));
6547 /* Note that NAME was looked up while the current class was being
6548 defined and that the result of that lookup was DECL. */
6551 maybe_note_name_used_in_class (tree name, tree decl)
6553 splay_tree names_used;
6555 /* If we're not defining a class, there's nothing to do. */
6556 if (!(innermost_scope_kind() == sk_class
6557 && TYPE_BEING_DEFINED (current_class_type)))
6560 /* If there's already a binding for this NAME, then we don't have
6561 anything to worry about. */
6562 if (lookup_member (current_class_type, name,
6563 /*protect=*/0, /*want_type=*/false))
6566 if (!current_class_stack[current_class_depth - 1].names_used)
6567 current_class_stack[current_class_depth - 1].names_used
6568 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6569 names_used = current_class_stack[current_class_depth - 1].names_used;
6571 splay_tree_insert (names_used,
6572 (splay_tree_key) name,
6573 (splay_tree_value) decl);
6576 /* Note that NAME was declared (as DECL) in the current class. Check
6577 to see that the declaration is valid. */
6580 note_name_declared_in_class (tree name, tree decl)
6582 splay_tree names_used;
6585 /* Look to see if we ever used this name. */
6587 = current_class_stack[current_class_depth - 1].names_used;
6591 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6594 /* [basic.scope.class]
6596 A name N used in a class S shall refer to the same declaration
6597 in its context and when re-evaluated in the completed scope of
6599 permerror (input_location, "declaration of %q#D", decl);
6600 permerror (input_location, "changes meaning of %qD from %q+#D",
6601 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6605 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6606 Secondary vtables are merged with primary vtables; this function
6607 will return the VAR_DECL for the primary vtable. */
6610 get_vtbl_decl_for_binfo (tree binfo)
6614 decl = BINFO_VTABLE (binfo);
6615 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR)
6617 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6618 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6621 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6626 /* Returns the binfo for the primary base of BINFO. If the resulting
6627 BINFO is a virtual base, and it is inherited elsewhere in the
6628 hierarchy, then the returned binfo might not be the primary base of
6629 BINFO in the complete object. Check BINFO_PRIMARY_P or
6630 BINFO_LOST_PRIMARY_P to be sure. */
6633 get_primary_binfo (tree binfo)
6637 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6641 return copied_binfo (primary_base, binfo);
6644 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6647 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6650 fprintf (stream, "%*s", indent, "");
6654 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6655 INDENT should be zero when called from the top level; it is
6656 incremented recursively. IGO indicates the next expected BINFO in
6657 inheritance graph ordering. */
6660 dump_class_hierarchy_r (FILE *stream,
6670 indented = maybe_indent_hierarchy (stream, indent, 0);
6671 fprintf (stream, "%s (0x%lx) ",
6672 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6673 (unsigned long) binfo);
6676 fprintf (stream, "alternative-path\n");
6679 igo = TREE_CHAIN (binfo);
6681 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6682 tree_low_cst (BINFO_OFFSET (binfo), 0));
6683 if (is_empty_class (BINFO_TYPE (binfo)))
6684 fprintf (stream, " empty");
6685 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6686 fprintf (stream, " nearly-empty");
6687 if (BINFO_VIRTUAL_P (binfo))
6688 fprintf (stream, " virtual");
6689 fprintf (stream, "\n");
6692 if (BINFO_PRIMARY_P (binfo))
6694 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6695 fprintf (stream, " primary-for %s (0x%lx)",
6696 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6697 TFF_PLAIN_IDENTIFIER),
6698 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6700 if (BINFO_LOST_PRIMARY_P (binfo))
6702 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6703 fprintf (stream, " lost-primary");
6706 fprintf (stream, "\n");
6708 if (!(flags & TDF_SLIM))
6712 if (BINFO_SUBVTT_INDEX (binfo))
6714 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6715 fprintf (stream, " subvttidx=%s",
6716 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6717 TFF_PLAIN_IDENTIFIER));
6719 if (BINFO_VPTR_INDEX (binfo))
6721 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6722 fprintf (stream, " vptridx=%s",
6723 expr_as_string (BINFO_VPTR_INDEX (binfo),
6724 TFF_PLAIN_IDENTIFIER));
6726 if (BINFO_VPTR_FIELD (binfo))
6728 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6729 fprintf (stream, " vbaseoffset=%s",
6730 expr_as_string (BINFO_VPTR_FIELD (binfo),
6731 TFF_PLAIN_IDENTIFIER));
6733 if (BINFO_VTABLE (binfo))
6735 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6736 fprintf (stream, " vptr=%s",
6737 expr_as_string (BINFO_VTABLE (binfo),
6738 TFF_PLAIN_IDENTIFIER));
6742 fprintf (stream, "\n");
6745 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6746 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6751 /* Dump the BINFO hierarchy for T. */
6754 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6756 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6757 fprintf (stream, " size=%lu align=%lu\n",
6758 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6759 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6760 fprintf (stream, " base size=%lu base align=%lu\n",
6761 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6763 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6765 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6766 fprintf (stream, "\n");
6769 /* Debug interface to hierarchy dumping. */
6772 debug_class (tree t)
6774 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6778 dump_class_hierarchy (tree t)
6781 FILE *stream = dump_begin (TDI_class, &flags);
6785 dump_class_hierarchy_1 (stream, flags, t);
6786 dump_end (TDI_class, stream);
6791 dump_array (FILE * stream, tree decl)
6794 unsigned HOST_WIDE_INT ix;
6796 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6798 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6800 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6801 fprintf (stream, " %s entries",
6802 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6803 TFF_PLAIN_IDENTIFIER));
6804 fprintf (stream, "\n");
6806 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6808 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6809 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6813 dump_vtable (tree t, tree binfo, tree vtable)
6816 FILE *stream = dump_begin (TDI_class, &flags);
6821 if (!(flags & TDF_SLIM))
6823 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6825 fprintf (stream, "%s for %s",
6826 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6827 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6830 if (!BINFO_VIRTUAL_P (binfo))
6831 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6832 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6834 fprintf (stream, "\n");
6835 dump_array (stream, vtable);
6836 fprintf (stream, "\n");
6839 dump_end (TDI_class, stream);
6843 dump_vtt (tree t, tree vtt)
6846 FILE *stream = dump_begin (TDI_class, &flags);
6851 if (!(flags & TDF_SLIM))
6853 fprintf (stream, "VTT for %s\n",
6854 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6855 dump_array (stream, vtt);
6856 fprintf (stream, "\n");
6859 dump_end (TDI_class, stream);
6862 /* Dump a function or thunk and its thunkees. */
6865 dump_thunk (FILE *stream, int indent, tree thunk)
6867 static const char spaces[] = " ";
6868 tree name = DECL_NAME (thunk);
6871 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6873 !DECL_THUNK_P (thunk) ? "function"
6874 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6875 name ? IDENTIFIER_POINTER (name) : "<unset>");
6876 if (DECL_THUNK_P (thunk))
6878 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6879 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6881 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6882 if (!virtual_adjust)
6884 else if (DECL_THIS_THUNK_P (thunk))
6885 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6886 tree_low_cst (virtual_adjust, 0));
6888 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6889 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6890 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6891 if (THUNK_ALIAS (thunk))
6892 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6894 fprintf (stream, "\n");
6895 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6896 dump_thunk (stream, indent + 2, thunks);
6899 /* Dump the thunks for FN. */
6902 debug_thunks (tree fn)
6904 dump_thunk (stderr, 0, fn);
6907 /* Virtual function table initialization. */
6909 /* Create all the necessary vtables for T and its base classes. */
6912 finish_vtbls (tree t)
6917 /* We lay out the primary and secondary vtables in one contiguous
6918 vtable. The primary vtable is first, followed by the non-virtual
6919 secondary vtables in inheritance graph order. */
6920 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6921 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6922 TYPE_BINFO (t), t, list);
6924 /* Then come the virtual bases, also in inheritance graph order. */
6925 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6927 if (!BINFO_VIRTUAL_P (vbase))
6929 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6932 if (BINFO_VTABLE (TYPE_BINFO (t)))
6933 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6936 /* Initialize the vtable for BINFO with the INITS. */
6939 initialize_vtable (tree binfo, tree inits)
6943 layout_vtable_decl (binfo, list_length (inits));
6944 decl = get_vtbl_decl_for_binfo (binfo);
6945 initialize_artificial_var (decl, inits);
6946 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6949 /* Build the VTT (virtual table table) for T.
6950 A class requires a VTT if it has virtual bases.
6953 1 - primary virtual pointer for complete object T
6954 2 - secondary VTTs for each direct non-virtual base of T which requires a
6956 3 - secondary virtual pointers for each direct or indirect base of T which
6957 has virtual bases or is reachable via a virtual path from T.
6958 4 - secondary VTTs for each direct or indirect virtual base of T.
6960 Secondary VTTs look like complete object VTTs without part 4. */
6970 /* Build up the initializers for the VTT. */
6972 index = size_zero_node;
6973 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6975 /* If we didn't need a VTT, we're done. */
6979 /* Figure out the type of the VTT. */
6980 type = build_index_type (size_int (list_length (inits) - 1));
6981 type = build_cplus_array_type (const_ptr_type_node, type);
6983 /* Now, build the VTT object itself. */
6984 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
6985 initialize_artificial_var (vtt, inits);
6986 /* Add the VTT to the vtables list. */
6987 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6988 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
6993 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
6994 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
6995 and CHAIN the vtable pointer for this binfo after construction is
6996 complete. VALUE can also be another BINFO, in which case we recurse. */
6999 binfo_ctor_vtable (tree binfo)
7005 vt = BINFO_VTABLE (binfo);
7006 if (TREE_CODE (vt) == TREE_LIST)
7007 vt = TREE_VALUE (vt);
7008 if (TREE_CODE (vt) == TREE_BINFO)
7017 /* Data for secondary VTT initialization. */
7018 typedef struct secondary_vptr_vtt_init_data_s
7020 /* Is this the primary VTT? */
7023 /* Current index into the VTT. */
7026 /* TREE_LIST of initializers built up. */
7029 /* The type being constructed by this secondary VTT. */
7030 tree type_being_constructed;
7031 } secondary_vptr_vtt_init_data;
7033 /* Recursively build the VTT-initializer for BINFO (which is in the
7034 hierarchy dominated by T). INITS points to the end of the initializer
7035 list to date. INDEX is the VTT index where the next element will be
7036 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7037 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7038 for virtual bases of T. When it is not so, we build the constructor
7039 vtables for the BINFO-in-T variant. */
7042 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
7047 tree secondary_vptrs;
7048 secondary_vptr_vtt_init_data data;
7049 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7051 /* We only need VTTs for subobjects with virtual bases. */
7052 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7055 /* We need to use a construction vtable if this is not the primary
7059 build_ctor_vtbl_group (binfo, t);
7061 /* Record the offset in the VTT where this sub-VTT can be found. */
7062 BINFO_SUBVTT_INDEX (binfo) = *index;
7065 /* Add the address of the primary vtable for the complete object. */
7066 init = binfo_ctor_vtable (binfo);
7067 *inits = build_tree_list (NULL_TREE, init);
7068 inits = &TREE_CHAIN (*inits);
7071 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7072 BINFO_VPTR_INDEX (binfo) = *index;
7074 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
7076 /* Recursively add the secondary VTTs for non-virtual bases. */
7077 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
7078 if (!BINFO_VIRTUAL_P (b))
7079 inits = build_vtt_inits (b, t, inits, index);
7081 /* Add secondary virtual pointers for all subobjects of BINFO with
7082 either virtual bases or reachable along a virtual path, except
7083 subobjects that are non-virtual primary bases. */
7084 data.top_level_p = top_level_p;
7085 data.index = *index;
7087 data.type_being_constructed = BINFO_TYPE (binfo);
7089 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
7091 *index = data.index;
7093 /* The secondary vptrs come back in reverse order. After we reverse
7094 them, and add the INITS, the last init will be the first element
7096 secondary_vptrs = data.inits;
7097 if (secondary_vptrs)
7099 *inits = nreverse (secondary_vptrs);
7100 inits = &TREE_CHAIN (secondary_vptrs);
7101 gcc_assert (*inits == NULL_TREE);
7105 /* Add the secondary VTTs for virtual bases in inheritance graph
7107 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
7109 if (!BINFO_VIRTUAL_P (b))
7112 inits = build_vtt_inits (b, t, inits, index);
7115 /* Remove the ctor vtables we created. */
7116 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
7121 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7122 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7125 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
7127 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
7129 /* We don't care about bases that don't have vtables. */
7130 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
7131 return dfs_skip_bases;
7133 /* We're only interested in proper subobjects of the type being
7135 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
7138 /* We're only interested in bases with virtual bases or reachable
7139 via a virtual path from the type being constructed. */
7140 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7141 || binfo_via_virtual (binfo, data->type_being_constructed)))
7142 return dfs_skip_bases;
7144 /* We're not interested in non-virtual primary bases. */
7145 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
7148 /* Record the index where this secondary vptr can be found. */
7149 if (data->top_level_p)
7151 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7152 BINFO_VPTR_INDEX (binfo) = data->index;
7154 if (BINFO_VIRTUAL_P (binfo))
7156 /* It's a primary virtual base, and this is not a
7157 construction vtable. Find the base this is primary of in
7158 the inheritance graph, and use that base's vtable
7160 while (BINFO_PRIMARY_P (binfo))
7161 binfo = BINFO_INHERITANCE_CHAIN (binfo);
7165 /* Add the initializer for the secondary vptr itself. */
7166 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
7168 /* Advance the vtt index. */
7169 data->index = size_binop (PLUS_EXPR, data->index,
7170 TYPE_SIZE_UNIT (ptr_type_node));
7175 /* Called from build_vtt_inits via dfs_walk. After building
7176 constructor vtables and generating the sub-vtt from them, we need
7177 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7178 binfo of the base whose sub vtt was generated. */
7181 dfs_fixup_binfo_vtbls (tree binfo, void* data)
7183 tree vtable = BINFO_VTABLE (binfo);
7185 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7186 /* If this class has no vtable, none of its bases do. */
7187 return dfs_skip_bases;
7190 /* This might be a primary base, so have no vtable in this
7194 /* If we scribbled the construction vtable vptr into BINFO, clear it
7196 if (TREE_CODE (vtable) == TREE_LIST
7197 && (TREE_PURPOSE (vtable) == (tree) data))
7198 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
7203 /* Build the construction vtable group for BINFO which is in the
7204 hierarchy dominated by T. */
7207 build_ctor_vtbl_group (tree binfo, tree t)
7216 /* See if we've already created this construction vtable group. */
7217 id = mangle_ctor_vtbl_for_type (t, binfo);
7218 if (IDENTIFIER_GLOBAL_VALUE (id))
7221 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
7222 /* Build a version of VTBL (with the wrong type) for use in
7223 constructing the addresses of secondary vtables in the
7224 construction vtable group. */
7225 vtbl = build_vtable (t, id, ptr_type_node);
7226 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
7227 list = build_tree_list (vtbl, NULL_TREE);
7228 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
7231 /* Add the vtables for each of our virtual bases using the vbase in T
7233 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7235 vbase = TREE_CHAIN (vbase))
7239 if (!BINFO_VIRTUAL_P (vbase))
7241 b = copied_binfo (vbase, binfo);
7243 accumulate_vtbl_inits (b, vbase, binfo, t, list);
7245 inits = TREE_VALUE (list);
7247 /* Figure out the type of the construction vtable. */
7248 type = build_index_type (size_int (list_length (inits) - 1));
7249 type = build_cplus_array_type (vtable_entry_type, type);
7251 TREE_TYPE (vtbl) = type;
7252 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE;
7253 layout_decl (vtbl, 0);
7255 /* Initialize the construction vtable. */
7256 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
7257 initialize_artificial_var (vtbl, inits);
7258 dump_vtable (t, binfo, vtbl);
7261 /* Add the vtbl initializers for BINFO (and its bases other than
7262 non-virtual primaries) to the list of INITS. BINFO is in the
7263 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7264 the constructor the vtbl inits should be accumulated for. (If this
7265 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7266 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7267 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7268 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7269 but are not necessarily the same in terms of layout. */
7272 accumulate_vtbl_inits (tree binfo,
7280 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7282 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7284 /* If it doesn't have a vptr, we don't do anything. */
7285 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7288 /* If we're building a construction vtable, we're not interested in
7289 subobjects that don't require construction vtables. */
7291 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7292 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7295 /* Build the initializers for the BINFO-in-T vtable. */
7297 = chainon (TREE_VALUE (inits),
7298 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7299 rtti_binfo, t, inits));
7301 /* Walk the BINFO and its bases. We walk in preorder so that as we
7302 initialize each vtable we can figure out at what offset the
7303 secondary vtable lies from the primary vtable. We can't use
7304 dfs_walk here because we need to iterate through bases of BINFO
7305 and RTTI_BINFO simultaneously. */
7306 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7308 /* Skip virtual bases. */
7309 if (BINFO_VIRTUAL_P (base_binfo))
7311 accumulate_vtbl_inits (base_binfo,
7312 BINFO_BASE_BINFO (orig_binfo, i),
7318 /* Called from accumulate_vtbl_inits. Returns the initializers for
7319 the BINFO vtable. */
7322 dfs_accumulate_vtbl_inits (tree binfo,
7328 tree inits = NULL_TREE;
7329 tree vtbl = NULL_TREE;
7330 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7333 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7335 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7336 primary virtual base. If it is not the same primary in
7337 the hierarchy of T, we'll need to generate a ctor vtable
7338 for it, to place at its location in T. If it is the same
7339 primary, we still need a VTT entry for the vtable, but it
7340 should point to the ctor vtable for the base it is a
7341 primary for within the sub-hierarchy of RTTI_BINFO.
7343 There are three possible cases:
7345 1) We are in the same place.
7346 2) We are a primary base within a lost primary virtual base of
7348 3) We are primary to something not a base of RTTI_BINFO. */
7351 tree last = NULL_TREE;
7353 /* First, look through the bases we are primary to for RTTI_BINFO
7354 or a virtual base. */
7356 while (BINFO_PRIMARY_P (b))
7358 b = BINFO_INHERITANCE_CHAIN (b);
7360 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7363 /* If we run out of primary links, keep looking down our
7364 inheritance chain; we might be an indirect primary. */
7365 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7366 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7370 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7371 base B and it is a base of RTTI_BINFO, this is case 2. In
7372 either case, we share our vtable with LAST, i.e. the
7373 derived-most base within B of which we are a primary. */
7375 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7376 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7377 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7378 binfo_ctor_vtable after everything's been set up. */
7381 /* Otherwise, this is case 3 and we get our own. */
7383 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7391 /* Compute the initializer for this vtable. */
7392 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7395 /* Figure out the position to which the VPTR should point. */
7396 vtbl = TREE_PURPOSE (l);
7397 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7398 index = size_binop (PLUS_EXPR,
7399 size_int (non_fn_entries),
7400 size_int (list_length (TREE_VALUE (l))));
7401 index = size_binop (MULT_EXPR,
7402 TYPE_SIZE_UNIT (vtable_entry_type),
7404 vtbl = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7408 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7409 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7410 straighten this out. */
7411 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7412 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7415 /* For an ordinary vtable, set BINFO_VTABLE. */
7416 BINFO_VTABLE (binfo) = vtbl;
7421 static GTY(()) tree abort_fndecl_addr;
7423 /* Construct the initializer for BINFO's virtual function table. BINFO
7424 is part of the hierarchy dominated by T. If we're building a
7425 construction vtable, the ORIG_BINFO is the binfo we should use to
7426 find the actual function pointers to put in the vtable - but they
7427 can be overridden on the path to most-derived in the graph that
7428 ORIG_BINFO belongs. Otherwise,
7429 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7430 BINFO that should be indicated by the RTTI information in the
7431 vtable; it will be a base class of T, rather than T itself, if we
7432 are building a construction vtable.
7434 The value returned is a TREE_LIST suitable for wrapping in a
7435 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7436 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7437 number of non-function entries in the vtable.
7439 It might seem that this function should never be called with a
7440 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7441 base is always subsumed by a derived class vtable. However, when
7442 we are building construction vtables, we do build vtables for
7443 primary bases; we need these while the primary base is being
7447 build_vtbl_initializer (tree binfo,
7451 int* non_fn_entries_p)
7458 VEC(tree,gc) *vbases;
7460 /* Initialize VID. */
7461 memset (&vid, 0, sizeof (vid));
7464 vid.rtti_binfo = rtti_binfo;
7465 vid.last_init = &vid.inits;
7466 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7467 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7468 vid.generate_vcall_entries = true;
7469 /* The first vbase or vcall offset is at index -3 in the vtable. */
7470 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7472 /* Add entries to the vtable for RTTI. */
7473 build_rtti_vtbl_entries (binfo, &vid);
7475 /* Create an array for keeping track of the functions we've
7476 processed. When we see multiple functions with the same
7477 signature, we share the vcall offsets. */
7478 vid.fns = VEC_alloc (tree, gc, 32);
7479 /* Add the vcall and vbase offset entries. */
7480 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7482 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7483 build_vbase_offset_vtbl_entries. */
7484 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7485 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7486 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7488 /* If the target requires padding between data entries, add that now. */
7489 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7493 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7498 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7499 add = tree_cons (NULL_TREE,
7500 build1 (NOP_EXPR, vtable_entry_type,
7507 if (non_fn_entries_p)
7508 *non_fn_entries_p = list_length (vid.inits);
7510 /* Go through all the ordinary virtual functions, building up
7512 vfun_inits = NULL_TREE;
7513 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7517 tree fn, fn_original;
7518 tree init = NULL_TREE;
7522 if (DECL_THUNK_P (fn))
7524 if (!DECL_NAME (fn))
7526 if (THUNK_ALIAS (fn))
7528 fn = THUNK_ALIAS (fn);
7531 fn_original = THUNK_TARGET (fn);
7534 /* If the only definition of this function signature along our
7535 primary base chain is from a lost primary, this vtable slot will
7536 never be used, so just zero it out. This is important to avoid
7537 requiring extra thunks which cannot be generated with the function.
7539 We first check this in update_vtable_entry_for_fn, so we handle
7540 restored primary bases properly; we also need to do it here so we
7541 zero out unused slots in ctor vtables, rather than filling them
7542 with erroneous values (though harmless, apart from relocation
7544 for (b = binfo; ; b = get_primary_binfo (b))
7546 /* We found a defn before a lost primary; go ahead as normal. */
7547 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7550 /* The nearest definition is from a lost primary; clear the
7552 if (BINFO_LOST_PRIMARY_P (b))
7554 init = size_zero_node;
7561 /* Pull the offset for `this', and the function to call, out of
7563 delta = BV_DELTA (v);
7564 vcall_index = BV_VCALL_INDEX (v);
7566 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7567 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7569 /* You can't call an abstract virtual function; it's abstract.
7570 So, we replace these functions with __pure_virtual. */
7571 if (DECL_PURE_VIRTUAL_P (fn_original))
7574 if (abort_fndecl_addr == NULL)
7575 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7576 init = abort_fndecl_addr;
7580 if (!integer_zerop (delta) || vcall_index)
7582 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7583 if (!DECL_NAME (fn))
7586 /* Take the address of the function, considering it to be of an
7587 appropriate generic type. */
7588 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7592 /* And add it to the chain of initializers. */
7593 if (TARGET_VTABLE_USES_DESCRIPTORS)
7596 if (init == size_zero_node)
7597 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7598 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7600 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7602 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7603 TREE_OPERAND (init, 0),
7604 build_int_cst (NULL_TREE, i));
7605 TREE_CONSTANT (fdesc) = 1;
7607 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7611 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7614 /* The initializers for virtual functions were built up in reverse
7615 order; straighten them out now. */
7616 vfun_inits = nreverse (vfun_inits);
7618 /* The negative offset initializers are also in reverse order. */
7619 vid.inits = nreverse (vid.inits);
7621 /* Chain the two together. */
7622 return chainon (vid.inits, vfun_inits);
7625 /* Adds to vid->inits the initializers for the vbase and vcall
7626 offsets in BINFO, which is in the hierarchy dominated by T. */
7629 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7633 /* If this is a derived class, we must first create entries
7634 corresponding to the primary base class. */
7635 b = get_primary_binfo (binfo);
7637 build_vcall_and_vbase_vtbl_entries (b, vid);
7639 /* Add the vbase entries for this base. */
7640 build_vbase_offset_vtbl_entries (binfo, vid);
7641 /* Add the vcall entries for this base. */
7642 build_vcall_offset_vtbl_entries (binfo, vid);
7645 /* Returns the initializers for the vbase offset entries in the vtable
7646 for BINFO (which is part of the class hierarchy dominated by T), in
7647 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7648 where the next vbase offset will go. */
7651 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7655 tree non_primary_binfo;
7657 /* If there are no virtual baseclasses, then there is nothing to
7659 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7664 /* We might be a primary base class. Go up the inheritance hierarchy
7665 until we find the most derived class of which we are a primary base:
7666 it is the offset of that which we need to use. */
7667 non_primary_binfo = binfo;
7668 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7672 /* If we have reached a virtual base, then it must be a primary
7673 base (possibly multi-level) of vid->binfo, or we wouldn't
7674 have called build_vcall_and_vbase_vtbl_entries for it. But it
7675 might be a lost primary, so just skip down to vid->binfo. */
7676 if (BINFO_VIRTUAL_P (non_primary_binfo))
7678 non_primary_binfo = vid->binfo;
7682 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7683 if (get_primary_binfo (b) != non_primary_binfo)
7685 non_primary_binfo = b;
7688 /* Go through the virtual bases, adding the offsets. */
7689 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7691 vbase = TREE_CHAIN (vbase))
7696 if (!BINFO_VIRTUAL_P (vbase))
7699 /* Find the instance of this virtual base in the complete
7701 b = copied_binfo (vbase, binfo);
7703 /* If we've already got an offset for this virtual base, we
7704 don't need another one. */
7705 if (BINFO_VTABLE_PATH_MARKED (b))
7707 BINFO_VTABLE_PATH_MARKED (b) = 1;
7709 /* Figure out where we can find this vbase offset. */
7710 delta = size_binop (MULT_EXPR,
7713 TYPE_SIZE_UNIT (vtable_entry_type)));
7714 if (vid->primary_vtbl_p)
7715 BINFO_VPTR_FIELD (b) = delta;
7717 if (binfo != TYPE_BINFO (t))
7718 /* The vbase offset had better be the same. */
7719 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7721 /* The next vbase will come at a more negative offset. */
7722 vid->index = size_binop (MINUS_EXPR, vid->index,
7723 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7725 /* The initializer is the delta from BINFO to this virtual base.
7726 The vbase offsets go in reverse inheritance-graph order, and
7727 we are walking in inheritance graph order so these end up in
7729 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7732 = build_tree_list (NULL_TREE,
7733 fold_build1 (NOP_EXPR,
7736 vid->last_init = &TREE_CHAIN (*vid->last_init);
7740 /* Adds the initializers for the vcall offset entries in the vtable
7741 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7745 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7747 /* We only need these entries if this base is a virtual base. We
7748 compute the indices -- but do not add to the vtable -- when
7749 building the main vtable for a class. */
7750 if (binfo == TYPE_BINFO (vid->derived)
7751 || (BINFO_VIRTUAL_P (binfo)
7752 /* If BINFO is RTTI_BINFO, then (since BINFO does not
7753 correspond to VID->DERIVED), we are building a primary
7754 construction virtual table. Since this is a primary
7755 virtual table, we do not need the vcall offsets for
7757 && binfo != vid->rtti_binfo))
7759 /* We need a vcall offset for each of the virtual functions in this
7760 vtable. For example:
7762 class A { virtual void f (); };
7763 class B1 : virtual public A { virtual void f (); };
7764 class B2 : virtual public A { virtual void f (); };
7765 class C: public B1, public B2 { virtual void f (); };
7767 A C object has a primary base of B1, which has a primary base of A. A
7768 C also has a secondary base of B2, which no longer has a primary base
7769 of A. So the B2-in-C construction vtable needs a secondary vtable for
7770 A, which will adjust the A* to a B2* to call f. We have no way of
7771 knowing what (or even whether) this offset will be when we define B2,
7772 so we store this "vcall offset" in the A sub-vtable and look it up in
7773 a "virtual thunk" for B2::f.
7775 We need entries for all the functions in our primary vtable and
7776 in our non-virtual bases' secondary vtables. */
7778 /* If we are just computing the vcall indices -- but do not need
7779 the actual entries -- not that. */
7780 if (!BINFO_VIRTUAL_P (binfo))
7781 vid->generate_vcall_entries = false;
7782 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7783 add_vcall_offset_vtbl_entries_r (binfo, vid);
7787 /* Build vcall offsets, starting with those for BINFO. */
7790 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7796 /* Don't walk into virtual bases -- except, of course, for the
7797 virtual base for which we are building vcall offsets. Any
7798 primary virtual base will have already had its offsets generated
7799 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7800 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7803 /* If BINFO has a primary base, process it first. */
7804 primary_binfo = get_primary_binfo (binfo);
7806 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7808 /* Add BINFO itself to the list. */
7809 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7811 /* Scan the non-primary bases of BINFO. */
7812 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7813 if (base_binfo != primary_binfo)
7814 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7817 /* Called from build_vcall_offset_vtbl_entries_r. */
7820 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7822 /* Make entries for the rest of the virtuals. */
7823 if (abi_version_at_least (2))
7827 /* The ABI requires that the methods be processed in declaration
7828 order. G++ 3.2 used the order in the vtable. */
7829 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7831 orig_fn = TREE_CHAIN (orig_fn))
7832 if (DECL_VINDEX (orig_fn))
7833 add_vcall_offset (orig_fn, binfo, vid);
7837 tree derived_virtuals;
7840 /* If BINFO is a primary base, the most derived class which has
7841 BINFO as a primary base; otherwise, just BINFO. */
7842 tree non_primary_binfo;
7844 /* We might be a primary base class. Go up the inheritance hierarchy
7845 until we find the most derived class of which we are a primary base:
7846 it is the BINFO_VIRTUALS there that we need to consider. */
7847 non_primary_binfo = binfo;
7848 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7852 /* If we have reached a virtual base, then it must be vid->vbase,
7853 because we ignore other virtual bases in
7854 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7855 base (possibly multi-level) of vid->binfo, or we wouldn't
7856 have called build_vcall_and_vbase_vtbl_entries for it. But it
7857 might be a lost primary, so just skip down to vid->binfo. */
7858 if (BINFO_VIRTUAL_P (non_primary_binfo))
7860 gcc_assert (non_primary_binfo == vid->vbase);
7861 non_primary_binfo = vid->binfo;
7865 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7866 if (get_primary_binfo (b) != non_primary_binfo)
7868 non_primary_binfo = b;
7871 if (vid->ctor_vtbl_p)
7872 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7873 where rtti_binfo is the most derived type. */
7875 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7877 for (base_virtuals = BINFO_VIRTUALS (binfo),
7878 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7879 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7881 base_virtuals = TREE_CHAIN (base_virtuals),
7882 derived_virtuals = TREE_CHAIN (derived_virtuals),
7883 orig_virtuals = TREE_CHAIN (orig_virtuals))
7887 /* Find the declaration that originally caused this function to
7888 be present in BINFO_TYPE (binfo). */
7889 orig_fn = BV_FN (orig_virtuals);
7891 /* When processing BINFO, we only want to generate vcall slots for
7892 function slots introduced in BINFO. So don't try to generate
7893 one if the function isn't even defined in BINFO. */
7894 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7897 add_vcall_offset (orig_fn, binfo, vid);
7902 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7905 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7911 /* If there is already an entry for a function with the same
7912 signature as FN, then we do not need a second vcall offset.
7913 Check the list of functions already present in the derived
7915 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7917 if (same_signature_p (derived_entry, orig_fn)
7918 /* We only use one vcall offset for virtual destructors,
7919 even though there are two virtual table entries. */
7920 || (DECL_DESTRUCTOR_P (derived_entry)
7921 && DECL_DESTRUCTOR_P (orig_fn)))
7925 /* If we are building these vcall offsets as part of building
7926 the vtable for the most derived class, remember the vcall
7928 if (vid->binfo == TYPE_BINFO (vid->derived))
7930 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7931 CLASSTYPE_VCALL_INDICES (vid->derived),
7933 elt->purpose = orig_fn;
7934 elt->value = vid->index;
7937 /* The next vcall offset will be found at a more negative
7939 vid->index = size_binop (MINUS_EXPR, vid->index,
7940 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7942 /* Keep track of this function. */
7943 VEC_safe_push (tree, gc, vid->fns, orig_fn);
7945 if (vid->generate_vcall_entries)
7950 /* Find the overriding function. */
7951 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7952 if (fn == error_mark_node)
7953 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7957 base = TREE_VALUE (fn);
7959 /* The vbase we're working on is a primary base of
7960 vid->binfo. But it might be a lost primary, so its
7961 BINFO_OFFSET might be wrong, so we just use the
7962 BINFO_OFFSET from vid->binfo. */
7963 vcall_offset = size_diffop (BINFO_OFFSET (base),
7964 BINFO_OFFSET (vid->binfo));
7965 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7968 /* Add the initializer to the vtable. */
7969 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7970 vid->last_init = &TREE_CHAIN (*vid->last_init);
7974 /* Return vtbl initializers for the RTTI entries corresponding to the
7975 BINFO's vtable. The RTTI entries should indicate the object given
7976 by VID->rtti_binfo. */
7979 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7988 basetype = BINFO_TYPE (binfo);
7989 t = BINFO_TYPE (vid->rtti_binfo);
7991 /* To find the complete object, we will first convert to our most
7992 primary base, and then add the offset in the vtbl to that value. */
7994 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
7995 && !BINFO_LOST_PRIMARY_P (b))
7999 primary_base = get_primary_binfo (b);
8000 gcc_assert (BINFO_PRIMARY_P (primary_base)
8001 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
8004 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
8006 /* The second entry is the address of the typeinfo object. */
8008 decl = build_address (get_tinfo_decl (t));
8010 decl = integer_zero_node;
8012 /* Convert the declaration to a type that can be stored in the
8014 init = build_nop (vfunc_ptr_type_node, decl);
8015 *vid->last_init = build_tree_list (NULL_TREE, init);
8016 vid->last_init = &TREE_CHAIN (*vid->last_init);
8018 /* Add the offset-to-top entry. It comes earlier in the vtable than
8019 the typeinfo entry. Convert the offset to look like a
8020 function pointer, so that we can put it in the vtable. */
8021 init = build_nop (vfunc_ptr_type_node, offset);
8022 *vid->last_init = build_tree_list (NULL_TREE, init);
8023 vid->last_init = &TREE_CHAIN (*vid->last_init);
8026 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8027 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8030 cp_fold_obj_type_ref (tree ref, tree known_type)
8032 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
8033 HOST_WIDE_INT i = 0;
8034 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
8039 i += (TARGET_VTABLE_USES_DESCRIPTORS
8040 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
8046 #ifdef ENABLE_CHECKING
8047 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
8048 DECL_VINDEX (fndecl)));
8051 cgraph_node (fndecl)->local.vtable_method = true;
8053 return build_address (fndecl);
8056 #include "gt-cp-class.h"