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);
628 assemble_external (vtbl);
630 aref = build_array_ref (vtbl, idx, input_location);
631 TREE_CONSTANT (aref) |= TREE_CONSTANT (vtbl) && TREE_CONSTANT (idx);
637 build_vtbl_ref (tree instance, tree idx)
639 tree aref = build_vtbl_ref_1 (instance, idx);
644 /* Given a stable object pointer INSTANCE_PTR, return an expression which
645 yields a function pointer corresponding to vtable element INDEX. */
648 build_vfn_ref (tree instance_ptr, tree idx)
652 aref = build_vtbl_ref_1 (cp_build_indirect_ref (instance_ptr, 0,
653 tf_warning_or_error),
656 /* When using function descriptors, the address of the
657 vtable entry is treated as a function pointer. */
658 if (TARGET_VTABLE_USES_DESCRIPTORS)
659 aref = build1 (NOP_EXPR, TREE_TYPE (aref),
660 cp_build_unary_op (ADDR_EXPR, aref, /*noconvert=*/1,
661 tf_warning_or_error));
663 /* Remember this as a method reference, for later devirtualization. */
664 aref = build3 (OBJ_TYPE_REF, TREE_TYPE (aref), aref, instance_ptr, idx);
669 /* Return the name of the virtual function table (as an IDENTIFIER_NODE)
670 for the given TYPE. */
673 get_vtable_name (tree type)
675 return mangle_vtbl_for_type (type);
678 /* DECL is an entity associated with TYPE, like a virtual table or an
679 implicitly generated constructor. Determine whether or not DECL
680 should have external or internal linkage at the object file
681 level. This routine does not deal with COMDAT linkage and other
682 similar complexities; it simply sets TREE_PUBLIC if it possible for
683 entities in other translation units to contain copies of DECL, in
687 set_linkage_according_to_type (tree type, tree decl)
689 /* If TYPE involves a local class in a function with internal
690 linkage, then DECL should have internal linkage too. Other local
691 classes have no linkage -- but if their containing functions
692 have external linkage, it makes sense for DECL to have external
693 linkage too. That will allow template definitions to be merged,
695 if (no_linkage_check (type, /*relaxed_p=*/true))
697 TREE_PUBLIC (decl) = 0;
698 DECL_INTERFACE_KNOWN (decl) = 1;
701 TREE_PUBLIC (decl) = 1;
704 /* Create a VAR_DECL for a primary or secondary vtable for CLASS_TYPE.
705 (For a secondary vtable for B-in-D, CLASS_TYPE should be D, not B.)
706 Use NAME for the name of the vtable, and VTABLE_TYPE for its type. */
709 build_vtable (tree class_type, tree name, tree vtable_type)
713 decl = build_lang_decl (VAR_DECL, name, vtable_type);
714 /* vtable names are already mangled; give them their DECL_ASSEMBLER_NAME
715 now to avoid confusion in mangle_decl. */
716 SET_DECL_ASSEMBLER_NAME (decl, name);
717 DECL_CONTEXT (decl) = class_type;
718 DECL_ARTIFICIAL (decl) = 1;
719 TREE_STATIC (decl) = 1;
720 TREE_READONLY (decl) = 1;
721 DECL_VIRTUAL_P (decl) = 1;
722 DECL_ALIGN (decl) = TARGET_VTABLE_ENTRY_ALIGN;
723 DECL_VTABLE_OR_VTT_P (decl) = 1;
724 /* At one time the vtable info was grabbed 2 words at a time. This
725 fails on sparc unless you have 8-byte alignment. (tiemann) */
726 DECL_ALIGN (decl) = MAX (TYPE_ALIGN (double_type_node),
728 set_linkage_according_to_type (class_type, decl);
729 /* The vtable has not been defined -- yet. */
730 DECL_EXTERNAL (decl) = 1;
731 DECL_NOT_REALLY_EXTERN (decl) = 1;
733 /* Mark the VAR_DECL node representing the vtable itself as a
734 "gratuitous" one, thereby forcing dwarfout.c to ignore it. It
735 is rather important that such things be ignored because any
736 effort to actually generate DWARF for them will run into
737 trouble when/if we encounter code like:
740 struct S { virtual void member (); };
742 because the artificial declaration of the vtable itself (as
743 manufactured by the g++ front end) will say that the vtable is
744 a static member of `S' but only *after* the debug output for
745 the definition of `S' has already been output. This causes
746 grief because the DWARF entry for the definition of the vtable
747 will try to refer back to an earlier *declaration* of the
748 vtable as a static member of `S' and there won't be one. We
749 might be able to arrange to have the "vtable static member"
750 attached to the member list for `S' before the debug info for
751 `S' get written (which would solve the problem) but that would
752 require more intrusive changes to the g++ front end. */
753 DECL_IGNORED_P (decl) = 1;
758 /* Get the VAR_DECL of the vtable for TYPE. TYPE need not be polymorphic,
759 or even complete. If this does not exist, create it. If COMPLETE is
760 nonzero, then complete the definition of it -- that will render it
761 impossible to actually build the vtable, but is useful to get at those
762 which are known to exist in the runtime. */
765 get_vtable_decl (tree type, int complete)
769 if (CLASSTYPE_VTABLES (type))
770 return CLASSTYPE_VTABLES (type);
772 decl = build_vtable (type, get_vtable_name (type), vtbl_type_node);
773 CLASSTYPE_VTABLES (type) = decl;
777 DECL_EXTERNAL (decl) = 1;
778 finish_decl (decl, NULL_TREE, NULL_TREE);
784 /* Build the primary virtual function table for TYPE. If BINFO is
785 non-NULL, build the vtable starting with the initial approximation
786 that it is the same as the one which is the head of the association
787 list. Returns a nonzero value if a new vtable is actually
791 build_primary_vtable (tree binfo, tree type)
796 decl = get_vtable_decl (type, /*complete=*/0);
800 if (BINFO_NEW_VTABLE_MARKED (binfo))
801 /* We have already created a vtable for this base, so there's
802 no need to do it again. */
805 virtuals = copy_list (BINFO_VIRTUALS (binfo));
806 TREE_TYPE (decl) = TREE_TYPE (get_vtbl_decl_for_binfo (binfo));
807 DECL_SIZE (decl) = TYPE_SIZE (TREE_TYPE (decl));
808 DECL_SIZE_UNIT (decl) = TYPE_SIZE_UNIT (TREE_TYPE (decl));
812 gcc_assert (TREE_TYPE (decl) == vtbl_type_node);
813 virtuals = NULL_TREE;
816 #ifdef GATHER_STATISTICS
818 n_vtable_elems += list_length (virtuals);
821 /* Initialize the association list for this type, based
822 on our first approximation. */
823 BINFO_VTABLE (TYPE_BINFO (type)) = decl;
824 BINFO_VIRTUALS (TYPE_BINFO (type)) = virtuals;
825 SET_BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (type));
829 /* Give BINFO a new virtual function table which is initialized
830 with a skeleton-copy of its original initialization. The only
831 entry that changes is the `delta' entry, so we can really
832 share a lot of structure.
834 FOR_TYPE is the most derived type which caused this table to
837 Returns nonzero if we haven't met BINFO before.
839 The order in which vtables are built (by calling this function) for
840 an object must remain the same, otherwise a binary incompatibility
844 build_secondary_vtable (tree binfo)
846 if (BINFO_NEW_VTABLE_MARKED (binfo))
847 /* We already created a vtable for this base. There's no need to
851 /* Remember that we've created a vtable for this BINFO, so that we
852 don't try to do so again. */
853 SET_BINFO_NEW_VTABLE_MARKED (binfo);
855 /* Make fresh virtual list, so we can smash it later. */
856 BINFO_VIRTUALS (binfo) = copy_list (BINFO_VIRTUALS (binfo));
858 /* Secondary vtables are laid out as part of the same structure as
859 the primary vtable. */
860 BINFO_VTABLE (binfo) = NULL_TREE;
864 /* Create a new vtable for BINFO which is the hierarchy dominated by
865 T. Return nonzero if we actually created a new vtable. */
868 make_new_vtable (tree t, tree binfo)
870 if (binfo == TYPE_BINFO (t))
871 /* In this case, it is *type*'s vtable we are modifying. We start
872 with the approximation that its vtable is that of the
873 immediate base class. */
874 return build_primary_vtable (binfo, t);
876 /* This is our very own copy of `basetype' to play with. Later,
877 we will fill in all the virtual functions that override the
878 virtual functions in these base classes which are not defined
879 by the current type. */
880 return build_secondary_vtable (binfo);
883 /* Make *VIRTUALS, an entry on the BINFO_VIRTUALS list for BINFO
884 (which is in the hierarchy dominated by T) list FNDECL as its
885 BV_FN. DELTA is the required constant adjustment from the `this'
886 pointer where the vtable entry appears to the `this' required when
887 the function is actually called. */
890 modify_vtable_entry (tree t,
900 if (fndecl != BV_FN (v)
901 || !tree_int_cst_equal (delta, BV_DELTA (v)))
903 /* We need a new vtable for BINFO. */
904 if (make_new_vtable (t, binfo))
906 /* If we really did make a new vtable, we also made a copy
907 of the BINFO_VIRTUALS list. Now, we have to find the
908 corresponding entry in that list. */
909 *virtuals = BINFO_VIRTUALS (binfo);
910 while (BV_FN (*virtuals) != BV_FN (v))
911 *virtuals = TREE_CHAIN (*virtuals);
915 BV_DELTA (v) = delta;
916 BV_VCALL_INDEX (v) = NULL_TREE;
922 /* Add method METHOD to class TYPE. If USING_DECL is non-null, it is
923 the USING_DECL naming METHOD. Returns true if the method could be
924 added to the method vec. */
927 add_method (tree type, tree method, tree using_decl)
931 bool template_conv_p = false;
933 VEC(tree,gc) *method_vec;
935 bool insert_p = false;
939 if (method == error_mark_node)
942 complete_p = COMPLETE_TYPE_P (type);
943 conv_p = DECL_CONV_FN_P (method);
945 template_conv_p = (TREE_CODE (method) == TEMPLATE_DECL
946 && DECL_TEMPLATE_CONV_FN_P (method));
948 method_vec = CLASSTYPE_METHOD_VEC (type);
951 /* Make a new method vector. We start with 8 entries. We must
952 allocate at least two (for constructors and destructors), and
953 we're going to end up with an assignment operator at some
955 method_vec = VEC_alloc (tree, gc, 8);
956 /* Create slots for constructors and destructors. */
957 VEC_quick_push (tree, method_vec, NULL_TREE);
958 VEC_quick_push (tree, method_vec, NULL_TREE);
959 CLASSTYPE_METHOD_VEC (type) = method_vec;
962 /* Maintain TYPE_HAS_USER_CONSTRUCTOR, etc. */
963 grok_special_member_properties (method);
965 /* Constructors and destructors go in special slots. */
966 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (method))
967 slot = CLASSTYPE_CONSTRUCTOR_SLOT;
968 else if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
970 slot = CLASSTYPE_DESTRUCTOR_SLOT;
972 if (TYPE_FOR_JAVA (type))
974 if (!DECL_ARTIFICIAL (method))
975 error ("Java class %qT cannot have a destructor", type);
976 else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
977 error ("Java class %qT cannot have an implicit non-trivial "
987 /* See if we already have an entry with this name. */
988 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
989 VEC_iterate (tree, method_vec, slot, m);
995 if (TREE_CODE (m) == TEMPLATE_DECL
996 && DECL_TEMPLATE_CONV_FN_P (m))
1000 if (conv_p && !DECL_CONV_FN_P (m))
1002 if (DECL_NAME (m) == DECL_NAME (method))
1008 && !DECL_CONV_FN_P (m)
1009 && DECL_NAME (m) > DECL_NAME (method))
1013 current_fns = insert_p ? NULL_TREE : VEC_index (tree, method_vec, slot);
1015 /* Check to see if we've already got this method. */
1016 for (fns = current_fns; fns; fns = OVL_NEXT (fns))
1018 tree fn = OVL_CURRENT (fns);
1024 if (TREE_CODE (fn) != TREE_CODE (method))
1027 /* [over.load] Member function declarations with the
1028 same name and the same parameter types cannot be
1029 overloaded if any of them is a static member
1030 function declaration.
1032 [namespace.udecl] When a using-declaration brings names
1033 from a base class into a derived class scope, member
1034 functions in the derived class override and/or hide member
1035 functions with the same name and parameter types in a base
1036 class (rather than conflicting). */
1037 fn_type = TREE_TYPE (fn);
1038 method_type = TREE_TYPE (method);
1039 parms1 = TYPE_ARG_TYPES (fn_type);
1040 parms2 = TYPE_ARG_TYPES (method_type);
1042 /* Compare the quals on the 'this' parm. Don't compare
1043 the whole types, as used functions are treated as
1044 coming from the using class in overload resolution. */
1045 if (! DECL_STATIC_FUNCTION_P (fn)
1046 && ! DECL_STATIC_FUNCTION_P (method)
1047 && TREE_TYPE (TREE_VALUE (parms1)) != error_mark_node
1048 && TREE_TYPE (TREE_VALUE (parms2)) != error_mark_node
1049 && (TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms1)))
1050 != TYPE_QUALS (TREE_TYPE (TREE_VALUE (parms2)))))
1053 /* For templates, the return type and template parameters
1054 must be identical. */
1055 if (TREE_CODE (fn) == TEMPLATE_DECL
1056 && (!same_type_p (TREE_TYPE (fn_type),
1057 TREE_TYPE (method_type))
1058 || !comp_template_parms (DECL_TEMPLATE_PARMS (fn),
1059 DECL_TEMPLATE_PARMS (method))))
1062 if (! DECL_STATIC_FUNCTION_P (fn))
1063 parms1 = TREE_CHAIN (parms1);
1064 if (! DECL_STATIC_FUNCTION_P (method))
1065 parms2 = TREE_CHAIN (parms2);
1067 if (compparms (parms1, parms2)
1068 && (!DECL_CONV_FN_P (fn)
1069 || same_type_p (TREE_TYPE (fn_type),
1070 TREE_TYPE (method_type))))
1074 if (DECL_CONTEXT (fn) == type)
1075 /* Defer to the local function. */
1077 if (DECL_CONTEXT (fn) == DECL_CONTEXT (method))
1078 error ("repeated using declaration %q+D", using_decl);
1080 error ("using declaration %q+D conflicts with a previous using declaration",
1085 error ("%q+#D cannot be overloaded", method);
1086 error ("with %q+#D", fn);
1089 /* We don't call duplicate_decls here to merge the
1090 declarations because that will confuse things if the
1091 methods have inline definitions. In particular, we
1092 will crash while processing the definitions. */
1097 /* A class should never have more than one destructor. */
1098 if (current_fns && DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (method))
1101 /* Add the new binding. */
1102 overload = build_overload (method, current_fns);
1105 TYPE_HAS_CONVERSION (type) = 1;
1106 else if (slot >= CLASSTYPE_FIRST_CONVERSION_SLOT && !complete_p)
1107 push_class_level_binding (DECL_NAME (method), overload);
1113 /* We only expect to add few methods in the COMPLETE_P case, so
1114 just make room for one more method in that case. */
1116 reallocated = VEC_reserve_exact (tree, gc, method_vec, 1);
1118 reallocated = VEC_reserve (tree, gc, method_vec, 1);
1120 CLASSTYPE_METHOD_VEC (type) = method_vec;
1121 if (slot == VEC_length (tree, method_vec))
1122 VEC_quick_push (tree, method_vec, overload);
1124 VEC_quick_insert (tree, method_vec, slot, overload);
1127 /* Replace the current slot. */
1128 VEC_replace (tree, method_vec, slot, overload);
1132 /* Subroutines of finish_struct. */
1134 /* Change the access of FDECL to ACCESS in T. Return 1 if change was
1135 legit, otherwise return 0. */
1138 alter_access (tree t, tree fdecl, tree access)
1142 if (!DECL_LANG_SPECIFIC (fdecl))
1143 retrofit_lang_decl (fdecl);
1145 gcc_assert (!DECL_DISCRIMINATOR_P (fdecl));
1147 elem = purpose_member (t, DECL_ACCESS (fdecl));
1150 if (TREE_VALUE (elem) != access)
1152 if (TREE_CODE (TREE_TYPE (fdecl)) == FUNCTION_DECL)
1153 error ("conflicting access specifications for method"
1154 " %q+D, ignored", TREE_TYPE (fdecl));
1156 error ("conflicting access specifications for field %qE, ignored",
1161 /* They're changing the access to the same thing they changed
1162 it to before. That's OK. */
1168 perform_or_defer_access_check (TYPE_BINFO (t), fdecl, fdecl);
1169 DECL_ACCESS (fdecl) = tree_cons (t, access, DECL_ACCESS (fdecl));
1175 /* Process the USING_DECL, which is a member of T. */
1178 handle_using_decl (tree using_decl, tree t)
1180 tree decl = USING_DECL_DECLS (using_decl);
1181 tree name = DECL_NAME (using_decl);
1183 = TREE_PRIVATE (using_decl) ? access_private_node
1184 : TREE_PROTECTED (using_decl) ? access_protected_node
1185 : access_public_node;
1186 tree flist = NULL_TREE;
1189 gcc_assert (!processing_template_decl && decl);
1191 old_value = lookup_member (t, name, /*protect=*/0, /*want_type=*/false);
1194 if (is_overloaded_fn (old_value))
1195 old_value = OVL_CURRENT (old_value);
1197 if (DECL_P (old_value) && DECL_CONTEXT (old_value) == t)
1200 old_value = NULL_TREE;
1203 cp_emit_debug_info_for_using (decl, USING_DECL_SCOPE (using_decl));
1205 if (is_overloaded_fn (decl))
1210 else if (is_overloaded_fn (old_value))
1213 /* It's OK to use functions from a base when there are functions with
1214 the same name already present in the current class. */;
1217 error ("%q+D invalid in %q#T", using_decl, t);
1218 error (" because of local method %q+#D with same name",
1219 OVL_CURRENT (old_value));
1223 else if (!DECL_ARTIFICIAL (old_value))
1225 error ("%q+D invalid in %q#T", using_decl, t);
1226 error (" because of local member %q+#D with same name", old_value);
1230 /* Make type T see field decl FDECL with access ACCESS. */
1232 for (; flist; flist = OVL_NEXT (flist))
1234 add_method (t, OVL_CURRENT (flist), using_decl);
1235 alter_access (t, OVL_CURRENT (flist), access);
1238 alter_access (t, decl, access);
1241 /* Run through the base classes of T, updating CANT_HAVE_CONST_CTOR_P,
1242 and NO_CONST_ASN_REF_P. Also set flag bits in T based on
1243 properties of the bases. */
1246 check_bases (tree t,
1247 int* cant_have_const_ctor_p,
1248 int* no_const_asn_ref_p)
1251 int seen_non_virtual_nearly_empty_base_p;
1255 seen_non_virtual_nearly_empty_base_p = 0;
1257 for (binfo = TYPE_BINFO (t), i = 0;
1258 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
1260 tree basetype = TREE_TYPE (base_binfo);
1262 gcc_assert (COMPLETE_TYPE_P (basetype));
1264 /* Effective C++ rule 14. We only need to check TYPE_POLYMORPHIC_P
1265 here because the case of virtual functions but non-virtual
1266 dtor is handled in finish_struct_1. */
1267 if (!TYPE_POLYMORPHIC_P (basetype))
1268 warning (OPT_Weffc__,
1269 "base class %q#T has a non-virtual destructor", basetype);
1271 /* If the base class doesn't have copy constructors or
1272 assignment operators that take const references, then the
1273 derived class cannot have such a member automatically
1275 if (! TYPE_HAS_CONST_INIT_REF (basetype))
1276 *cant_have_const_ctor_p = 1;
1277 if (TYPE_HAS_ASSIGN_REF (basetype)
1278 && !TYPE_HAS_CONST_ASSIGN_REF (basetype))
1279 *no_const_asn_ref_p = 1;
1281 if (BINFO_VIRTUAL_P (base_binfo))
1282 /* A virtual base does not effect nearly emptiness. */
1284 else if (CLASSTYPE_NEARLY_EMPTY_P (basetype))
1286 if (seen_non_virtual_nearly_empty_base_p)
1287 /* And if there is more than one nearly empty base, then the
1288 derived class is not nearly empty either. */
1289 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1291 /* Remember we've seen one. */
1292 seen_non_virtual_nearly_empty_base_p = 1;
1294 else if (!is_empty_class (basetype))
1295 /* If the base class is not empty or nearly empty, then this
1296 class cannot be nearly empty. */
1297 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
1299 /* A lot of properties from the bases also apply to the derived
1301 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (basetype);
1302 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
1303 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (basetype);
1304 TYPE_HAS_COMPLEX_ASSIGN_REF (t)
1305 |= TYPE_HAS_COMPLEX_ASSIGN_REF (basetype);
1306 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (basetype);
1307 TYPE_POLYMORPHIC_P (t) |= TYPE_POLYMORPHIC_P (basetype);
1308 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t)
1309 |= CLASSTYPE_CONTAINS_EMPTY_CLASS_P (basetype);
1310 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (basetype);
1314 /* Determine all the primary bases within T. Sets BINFO_PRIMARY_BASE_P for
1315 those that are primaries. Sets BINFO_LOST_PRIMARY_P for those
1316 that have had a nearly-empty virtual primary base stolen by some
1317 other base in the hierarchy. Determines CLASSTYPE_PRIMARY_BASE for
1321 determine_primary_bases (tree t)
1324 tree primary = NULL_TREE;
1325 tree type_binfo = TYPE_BINFO (t);
1328 /* Determine the primary bases of our bases. */
1329 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1330 base_binfo = TREE_CHAIN (base_binfo))
1332 tree primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (base_binfo));
1334 /* See if we're the non-virtual primary of our inheritance
1336 if (!BINFO_VIRTUAL_P (base_binfo))
1338 tree parent = BINFO_INHERITANCE_CHAIN (base_binfo);
1339 tree parent_primary = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (parent));
1342 && SAME_BINFO_TYPE_P (BINFO_TYPE (base_binfo),
1343 BINFO_TYPE (parent_primary)))
1344 /* We are the primary binfo. */
1345 BINFO_PRIMARY_P (base_binfo) = 1;
1347 /* Determine if we have a virtual primary base, and mark it so.
1349 if (primary && BINFO_VIRTUAL_P (primary))
1351 tree this_primary = copied_binfo (primary, base_binfo);
1353 if (BINFO_PRIMARY_P (this_primary))
1354 /* Someone already claimed this base. */
1355 BINFO_LOST_PRIMARY_P (base_binfo) = 1;
1360 BINFO_PRIMARY_P (this_primary) = 1;
1361 BINFO_INHERITANCE_CHAIN (this_primary) = base_binfo;
1363 /* A virtual binfo might have been copied from within
1364 another hierarchy. As we're about to use it as a
1365 primary base, make sure the offsets match. */
1366 delta = size_diffop (convert (ssizetype,
1367 BINFO_OFFSET (base_binfo)),
1369 BINFO_OFFSET (this_primary)));
1371 propagate_binfo_offsets (this_primary, delta);
1376 /* First look for a dynamic direct non-virtual base. */
1377 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, base_binfo); i++)
1379 tree basetype = BINFO_TYPE (base_binfo);
1381 if (TYPE_CONTAINS_VPTR_P (basetype) && !BINFO_VIRTUAL_P (base_binfo))
1383 primary = base_binfo;
1388 /* A "nearly-empty" virtual base class can be the primary base
1389 class, if no non-virtual polymorphic base can be found. Look for
1390 a nearly-empty virtual dynamic base that is not already a primary
1391 base of something in the hierarchy. If there is no such base,
1392 just pick the first nearly-empty virtual base. */
1394 for (base_binfo = TREE_CHAIN (type_binfo); base_binfo;
1395 base_binfo = TREE_CHAIN (base_binfo))
1396 if (BINFO_VIRTUAL_P (base_binfo)
1397 && CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (base_binfo)))
1399 if (!BINFO_PRIMARY_P (base_binfo))
1401 /* Found one that is not primary. */
1402 primary = base_binfo;
1406 /* Remember the first candidate. */
1407 primary = base_binfo;
1411 /* If we've got a primary base, use it. */
1414 tree basetype = BINFO_TYPE (primary);
1416 CLASSTYPE_PRIMARY_BINFO (t) = primary;
1417 if (BINFO_PRIMARY_P (primary))
1418 /* We are stealing a primary base. */
1419 BINFO_LOST_PRIMARY_P (BINFO_INHERITANCE_CHAIN (primary)) = 1;
1420 BINFO_PRIMARY_P (primary) = 1;
1421 if (BINFO_VIRTUAL_P (primary))
1425 BINFO_INHERITANCE_CHAIN (primary) = type_binfo;
1426 /* A virtual binfo might have been copied from within
1427 another hierarchy. As we're about to use it as a primary
1428 base, make sure the offsets match. */
1429 delta = size_diffop (ssize_int (0),
1430 convert (ssizetype, BINFO_OFFSET (primary)));
1432 propagate_binfo_offsets (primary, delta);
1435 primary = TYPE_BINFO (basetype);
1437 TYPE_VFIELD (t) = TYPE_VFIELD (basetype);
1438 BINFO_VTABLE (type_binfo) = BINFO_VTABLE (primary);
1439 BINFO_VIRTUALS (type_binfo) = BINFO_VIRTUALS (primary);
1443 /* Update the variant types of T. */
1446 fixup_type_variants (tree t)
1453 for (variants = TYPE_NEXT_VARIANT (t);
1455 variants = TYPE_NEXT_VARIANT (variants))
1457 /* These fields are in the _TYPE part of the node, not in
1458 the TYPE_LANG_SPECIFIC component, so they are not shared. */
1459 TYPE_HAS_USER_CONSTRUCTOR (variants) = TYPE_HAS_USER_CONSTRUCTOR (t);
1460 TYPE_NEEDS_CONSTRUCTING (variants) = TYPE_NEEDS_CONSTRUCTING (t);
1461 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (variants)
1462 = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
1464 TYPE_POLYMORPHIC_P (variants) = TYPE_POLYMORPHIC_P (t);
1466 TYPE_BINFO (variants) = TYPE_BINFO (t);
1468 /* Copy whatever these are holding today. */
1469 TYPE_VFIELD (variants) = TYPE_VFIELD (t);
1470 TYPE_METHODS (variants) = TYPE_METHODS (t);
1471 TYPE_FIELDS (variants) = TYPE_FIELDS (t);
1473 /* All variants of a class have the same attributes. */
1474 TYPE_ATTRIBUTES (variants) = TYPE_ATTRIBUTES (t);
1479 /* Set memoizing fields and bits of T (and its variants) for later
1483 finish_struct_bits (tree t)
1485 /* Fix up variants (if any). */
1486 fixup_type_variants (t);
1488 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) && TYPE_POLYMORPHIC_P (t))
1489 /* For a class w/o baseclasses, 'finish_struct' has set
1490 CLASSTYPE_PURE_VIRTUALS correctly (by definition).
1491 Similarly for a class whose base classes do not have vtables.
1492 When neither of these is true, we might have removed abstract
1493 virtuals (by providing a definition), added some (by declaring
1494 new ones), or redeclared ones from a base class. We need to
1495 recalculate what's really an abstract virtual at this point (by
1496 looking in the vtables). */
1497 get_pure_virtuals (t);
1499 /* If this type has a copy constructor or a destructor, force its
1500 mode to be BLKmode, and force its TREE_ADDRESSABLE bit to be
1501 nonzero. This will cause it to be passed by invisible reference
1502 and prevent it from being returned in a register. */
1503 if (! TYPE_HAS_TRIVIAL_INIT_REF (t) || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
1506 DECL_MODE (TYPE_MAIN_DECL (t)) = BLKmode;
1507 for (variants = t; variants; variants = TYPE_NEXT_VARIANT (variants))
1509 SET_TYPE_MODE (variants, BLKmode);
1510 TREE_ADDRESSABLE (variants) = 1;
1515 /* Issue warnings about T having private constructors, but no friends,
1518 HAS_NONPRIVATE_METHOD is nonzero if T has any non-private methods or
1519 static members. HAS_NONPRIVATE_STATIC_FN is nonzero if T has any
1520 non-private static member functions. */
1523 maybe_warn_about_overly_private_class (tree t)
1525 int has_member_fn = 0;
1526 int has_nonprivate_method = 0;
1529 if (!warn_ctor_dtor_privacy
1530 /* If the class has friends, those entities might create and
1531 access instances, so we should not warn. */
1532 || (CLASSTYPE_FRIEND_CLASSES (t)
1533 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))
1534 /* We will have warned when the template was declared; there's
1535 no need to warn on every instantiation. */
1536 || CLASSTYPE_TEMPLATE_INSTANTIATION (t))
1537 /* There's no reason to even consider warning about this
1541 /* We only issue one warning, if more than one applies, because
1542 otherwise, on code like:
1545 // Oops - forgot `public:'
1551 we warn several times about essentially the same problem. */
1553 /* Check to see if all (non-constructor, non-destructor) member
1554 functions are private. (Since there are no friends or
1555 non-private statics, we can't ever call any of the private member
1557 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
1558 /* We're not interested in compiler-generated methods; they don't
1559 provide any way to call private members. */
1560 if (!DECL_ARTIFICIAL (fn))
1562 if (!TREE_PRIVATE (fn))
1564 if (DECL_STATIC_FUNCTION_P (fn))
1565 /* A non-private static member function is just like a
1566 friend; it can create and invoke private member
1567 functions, and be accessed without a class
1571 has_nonprivate_method = 1;
1572 /* Keep searching for a static member function. */
1574 else if (!DECL_CONSTRUCTOR_P (fn) && !DECL_DESTRUCTOR_P (fn))
1578 if (!has_nonprivate_method && has_member_fn)
1580 /* There are no non-private methods, and there's at least one
1581 private member function that isn't a constructor or
1582 destructor. (If all the private members are
1583 constructors/destructors we want to use the code below that
1584 issues error messages specifically referring to
1585 constructors/destructors.) */
1587 tree binfo = TYPE_BINFO (t);
1589 for (i = 0; i != BINFO_N_BASE_BINFOS (binfo); i++)
1590 if (BINFO_BASE_ACCESS (binfo, i) != access_private_node)
1592 has_nonprivate_method = 1;
1595 if (!has_nonprivate_method)
1597 warning (OPT_Wctor_dtor_privacy,
1598 "all member functions in class %qT are private", t);
1603 /* Even if some of the member functions are non-private, the class
1604 won't be useful for much if all the constructors or destructors
1605 are private: such an object can never be created or destroyed. */
1606 fn = CLASSTYPE_DESTRUCTORS (t);
1607 if (fn && TREE_PRIVATE (fn))
1609 warning (OPT_Wctor_dtor_privacy,
1610 "%q#T only defines a private destructor and has no friends",
1615 /* Warn about classes that have private constructors and no friends. */
1616 if (TYPE_HAS_USER_CONSTRUCTOR (t)
1617 /* Implicitly generated constructors are always public. */
1618 && (!CLASSTYPE_LAZY_DEFAULT_CTOR (t)
1619 || !CLASSTYPE_LAZY_COPY_CTOR (t)))
1621 int nonprivate_ctor = 0;
1623 /* If a non-template class does not define a copy
1624 constructor, one is defined for it, enabling it to avoid
1625 this warning. For a template class, this does not
1626 happen, and so we would normally get a warning on:
1628 template <class T> class C { private: C(); };
1630 To avoid this asymmetry, we check TYPE_HAS_INIT_REF. All
1631 complete non-template or fully instantiated classes have this
1633 if (!TYPE_HAS_INIT_REF (t))
1634 nonprivate_ctor = 1;
1636 for (fn = CLASSTYPE_CONSTRUCTORS (t); fn; fn = OVL_NEXT (fn))
1638 tree ctor = OVL_CURRENT (fn);
1639 /* Ideally, we wouldn't count copy constructors (or, in
1640 fact, any constructor that takes an argument of the
1641 class type as a parameter) because such things cannot
1642 be used to construct an instance of the class unless
1643 you already have one. But, for now at least, we're
1645 if (! TREE_PRIVATE (ctor))
1647 nonprivate_ctor = 1;
1652 if (nonprivate_ctor == 0)
1654 warning (OPT_Wctor_dtor_privacy,
1655 "%q#T only defines private constructors and has no friends",
1663 gt_pointer_operator new_value;
1667 /* Comparison function to compare two TYPE_METHOD_VEC entries by name. */
1670 method_name_cmp (const void* m1_p, const void* m2_p)
1672 const tree *const m1 = (const tree *) m1_p;
1673 const tree *const m2 = (const tree *) m2_p;
1675 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1677 if (*m1 == NULL_TREE)
1679 if (*m2 == NULL_TREE)
1681 if (DECL_NAME (OVL_CURRENT (*m1)) < DECL_NAME (OVL_CURRENT (*m2)))
1686 /* This routine compares two fields like method_name_cmp but using the
1687 pointer operator in resort_field_decl_data. */
1690 resort_method_name_cmp (const void* m1_p, const void* m2_p)
1692 const tree *const m1 = (const tree *) m1_p;
1693 const tree *const m2 = (const tree *) m2_p;
1694 if (*m1 == NULL_TREE && *m2 == NULL_TREE)
1696 if (*m1 == NULL_TREE)
1698 if (*m2 == NULL_TREE)
1701 tree d1 = DECL_NAME (OVL_CURRENT (*m1));
1702 tree d2 = DECL_NAME (OVL_CURRENT (*m2));
1703 resort_data.new_value (&d1, resort_data.cookie);
1704 resort_data.new_value (&d2, resort_data.cookie);
1711 /* Resort TYPE_METHOD_VEC because pointers have been reordered. */
1714 resort_type_method_vec (void* obj,
1715 void* orig_obj ATTRIBUTE_UNUSED ,
1716 gt_pointer_operator new_value,
1719 VEC(tree,gc) *method_vec = (VEC(tree,gc) *) obj;
1720 int len = VEC_length (tree, method_vec);
1724 /* The type conversion ops have to live at the front of the vec, so we
1726 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1727 VEC_iterate (tree, method_vec, slot, fn);
1729 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1734 resort_data.new_value = new_value;
1735 resort_data.cookie = cookie;
1736 qsort (VEC_address (tree, method_vec) + slot, len - slot, sizeof (tree),
1737 resort_method_name_cmp);
1741 /* Warn about duplicate methods in fn_fields.
1743 Sort methods that are not special (i.e., constructors, destructors,
1744 and type conversion operators) so that we can find them faster in
1748 finish_struct_methods (tree t)
1751 VEC(tree,gc) *method_vec;
1754 method_vec = CLASSTYPE_METHOD_VEC (t);
1758 len = VEC_length (tree, method_vec);
1760 /* Clear DECL_IN_AGGR_P for all functions. */
1761 for (fn_fields = TYPE_METHODS (t); fn_fields;
1762 fn_fields = TREE_CHAIN (fn_fields))
1763 DECL_IN_AGGR_P (fn_fields) = 0;
1765 /* Issue warnings about private constructors and such. If there are
1766 no methods, then some public defaults are generated. */
1767 maybe_warn_about_overly_private_class (t);
1769 /* The type conversion ops have to live at the front of the vec, so we
1771 for (slot = CLASSTYPE_FIRST_CONVERSION_SLOT;
1772 VEC_iterate (tree, method_vec, slot, fn_fields);
1774 if (!DECL_CONV_FN_P (OVL_CURRENT (fn_fields)))
1777 qsort (VEC_address (tree, method_vec) + slot,
1778 len-slot, sizeof (tree), method_name_cmp);
1781 /* Make BINFO's vtable have N entries, including RTTI entries,
1782 vbase and vcall offsets, etc. Set its type and call the back end
1786 layout_vtable_decl (tree binfo, int n)
1791 atype = build_cplus_array_type (vtable_entry_type,
1792 build_index_type (size_int (n - 1)));
1793 layout_type (atype);
1795 /* We may have to grow the vtable. */
1796 vtable = get_vtbl_decl_for_binfo (binfo);
1797 if (!same_type_p (TREE_TYPE (vtable), atype))
1799 TREE_TYPE (vtable) = atype;
1800 DECL_SIZE (vtable) = DECL_SIZE_UNIT (vtable) = NULL_TREE;
1801 layout_decl (vtable, 0);
1805 /* True iff FNDECL and BASE_FNDECL (both non-static member functions)
1806 have the same signature. */
1809 same_signature_p (const_tree fndecl, const_tree base_fndecl)
1811 /* One destructor overrides another if they are the same kind of
1813 if (DECL_DESTRUCTOR_P (base_fndecl) && DECL_DESTRUCTOR_P (fndecl)
1814 && special_function_p (base_fndecl) == special_function_p (fndecl))
1816 /* But a non-destructor never overrides a destructor, nor vice
1817 versa, nor do different kinds of destructors override
1818 one-another. For example, a complete object destructor does not
1819 override a deleting destructor. */
1820 if (DECL_DESTRUCTOR_P (base_fndecl) || DECL_DESTRUCTOR_P (fndecl))
1823 if (DECL_NAME (fndecl) == DECL_NAME (base_fndecl)
1824 || (DECL_CONV_FN_P (fndecl)
1825 && DECL_CONV_FN_P (base_fndecl)
1826 && same_type_p (DECL_CONV_FN_TYPE (fndecl),
1827 DECL_CONV_FN_TYPE (base_fndecl))))
1829 tree types, base_types;
1830 types = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1831 base_types = TYPE_ARG_TYPES (TREE_TYPE (base_fndecl));
1832 if ((TYPE_QUALS (TREE_TYPE (TREE_VALUE (base_types)))
1833 == TYPE_QUALS (TREE_TYPE (TREE_VALUE (types))))
1834 && compparms (TREE_CHAIN (base_types), TREE_CHAIN (types)))
1840 /* Returns TRUE if DERIVED is a binfo containing the binfo BASE as a
1844 base_derived_from (tree derived, tree base)
1848 for (probe = base; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1850 if (probe == derived)
1852 else if (BINFO_VIRTUAL_P (probe))
1853 /* If we meet a virtual base, we can't follow the inheritance
1854 any more. See if the complete type of DERIVED contains
1855 such a virtual base. */
1856 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (derived))
1862 typedef struct find_final_overrider_data_s {
1863 /* The function for which we are trying to find a final overrider. */
1865 /* The base class in which the function was declared. */
1866 tree declaring_base;
1867 /* The candidate overriders. */
1869 /* Path to most derived. */
1870 VEC(tree,heap) *path;
1871 } find_final_overrider_data;
1873 /* Add the overrider along the current path to FFOD->CANDIDATES.
1874 Returns true if an overrider was found; false otherwise. */
1877 dfs_find_final_overrider_1 (tree binfo,
1878 find_final_overrider_data *ffod,
1883 /* If BINFO is not the most derived type, try a more derived class.
1884 A definition there will overrider a definition here. */
1888 if (dfs_find_final_overrider_1
1889 (VEC_index (tree, ffod->path, depth), ffod, depth))
1893 method = look_for_overrides_here (BINFO_TYPE (binfo), ffod->fn);
1896 tree *candidate = &ffod->candidates;
1898 /* Remove any candidates overridden by this new function. */
1901 /* If *CANDIDATE overrides METHOD, then METHOD
1902 cannot override anything else on the list. */
1903 if (base_derived_from (TREE_VALUE (*candidate), binfo))
1905 /* If METHOD overrides *CANDIDATE, remove *CANDIDATE. */
1906 if (base_derived_from (binfo, TREE_VALUE (*candidate)))
1907 *candidate = TREE_CHAIN (*candidate);
1909 candidate = &TREE_CHAIN (*candidate);
1912 /* Add the new function. */
1913 ffod->candidates = tree_cons (method, binfo, ffod->candidates);
1920 /* Called from find_final_overrider via dfs_walk. */
1923 dfs_find_final_overrider_pre (tree binfo, void *data)
1925 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1927 if (binfo == ffod->declaring_base)
1928 dfs_find_final_overrider_1 (binfo, ffod, VEC_length (tree, ffod->path));
1929 VEC_safe_push (tree, heap, ffod->path, binfo);
1935 dfs_find_final_overrider_post (tree binfo ATTRIBUTE_UNUSED, void *data)
1937 find_final_overrider_data *ffod = (find_final_overrider_data *) data;
1938 VEC_pop (tree, ffod->path);
1943 /* Returns a TREE_LIST whose TREE_PURPOSE is the final overrider for
1944 FN and whose TREE_VALUE is the binfo for the base where the
1945 overriding occurs. BINFO (in the hierarchy dominated by the binfo
1946 DERIVED) is the base object in which FN is declared. */
1949 find_final_overrider (tree derived, tree binfo, tree fn)
1951 find_final_overrider_data ffod;
1953 /* Getting this right is a little tricky. This is valid:
1955 struct S { virtual void f (); };
1956 struct T { virtual void f (); };
1957 struct U : public S, public T { };
1959 even though calling `f' in `U' is ambiguous. But,
1961 struct R { virtual void f(); };
1962 struct S : virtual public R { virtual void f (); };
1963 struct T : virtual public R { virtual void f (); };
1964 struct U : public S, public T { };
1966 is not -- there's no way to decide whether to put `S::f' or
1967 `T::f' in the vtable for `R'.
1969 The solution is to look at all paths to BINFO. If we find
1970 different overriders along any two, then there is a problem. */
1971 if (DECL_THUNK_P (fn))
1972 fn = THUNK_TARGET (fn);
1974 /* Determine the depth of the hierarchy. */
1976 ffod.declaring_base = binfo;
1977 ffod.candidates = NULL_TREE;
1978 ffod.path = VEC_alloc (tree, heap, 30);
1980 dfs_walk_all (derived, dfs_find_final_overrider_pre,
1981 dfs_find_final_overrider_post, &ffod);
1983 VEC_free (tree, heap, ffod.path);
1985 /* If there was no winner, issue an error message. */
1986 if (!ffod.candidates || TREE_CHAIN (ffod.candidates))
1987 return error_mark_node;
1989 return ffod.candidates;
1992 /* Return the index of the vcall offset for FN when TYPE is used as a
1996 get_vcall_index (tree fn, tree type)
1998 VEC(tree_pair_s,gc) *indices = CLASSTYPE_VCALL_INDICES (type);
2002 for (ix = 0; VEC_iterate (tree_pair_s, indices, ix, p); ix++)
2003 if ((DECL_DESTRUCTOR_P (fn) && DECL_DESTRUCTOR_P (p->purpose))
2004 || same_signature_p (fn, p->purpose))
2007 /* There should always be an appropriate index. */
2011 /* Update an entry in the vtable for BINFO, which is in the hierarchy
2012 dominated by T. FN has been overridden in BINFO; VIRTUALS points to the
2013 corresponding position in the BINFO_VIRTUALS list. */
2016 update_vtable_entry_for_fn (tree t, tree binfo, tree fn, tree* virtuals,
2024 tree overrider_fn, overrider_target;
2025 tree target_fn = DECL_THUNK_P (fn) ? THUNK_TARGET (fn) : fn;
2026 tree over_return, base_return;
2029 /* Find the nearest primary base (possibly binfo itself) which defines
2030 this function; this is the class the caller will convert to when
2031 calling FN through BINFO. */
2032 for (b = binfo; ; b = get_primary_binfo (b))
2035 if (look_for_overrides_here (BINFO_TYPE (b), target_fn))
2038 /* The nearest definition is from a lost primary. */
2039 if (BINFO_LOST_PRIMARY_P (b))
2044 /* Find the final overrider. */
2045 overrider = find_final_overrider (TYPE_BINFO (t), b, target_fn);
2046 if (overrider == error_mark_node)
2048 error ("no unique final overrider for %qD in %qT", target_fn, t);
2051 overrider_target = overrider_fn = TREE_PURPOSE (overrider);
2053 /* Check for adjusting covariant return types. */
2054 over_return = TREE_TYPE (TREE_TYPE (overrider_target));
2055 base_return = TREE_TYPE (TREE_TYPE (target_fn));
2057 if (POINTER_TYPE_P (over_return)
2058 && TREE_CODE (over_return) == TREE_CODE (base_return)
2059 && CLASS_TYPE_P (TREE_TYPE (over_return))
2060 && CLASS_TYPE_P (TREE_TYPE (base_return))
2061 /* If the overrider is invalid, don't even try. */
2062 && !DECL_INVALID_OVERRIDER_P (overrider_target))
2064 /* If FN is a covariant thunk, we must figure out the adjustment
2065 to the final base FN was converting to. As OVERRIDER_TARGET might
2066 also be converting to the return type of FN, we have to
2067 combine the two conversions here. */
2068 tree fixed_offset, virtual_offset;
2070 over_return = TREE_TYPE (over_return);
2071 base_return = TREE_TYPE (base_return);
2073 if (DECL_THUNK_P (fn))
2075 gcc_assert (DECL_RESULT_THUNK_P (fn));
2076 fixed_offset = ssize_int (THUNK_FIXED_OFFSET (fn));
2077 virtual_offset = THUNK_VIRTUAL_OFFSET (fn);
2080 fixed_offset = virtual_offset = NULL_TREE;
2083 /* Find the equivalent binfo within the return type of the
2084 overriding function. We will want the vbase offset from
2086 virtual_offset = binfo_for_vbase (BINFO_TYPE (virtual_offset),
2088 else if (!same_type_ignoring_top_level_qualifiers_p
2089 (over_return, base_return))
2091 /* There was no existing virtual thunk (which takes
2092 precedence). So find the binfo of the base function's
2093 return type within the overriding function's return type.
2094 We cannot call lookup base here, because we're inside a
2095 dfs_walk, and will therefore clobber the BINFO_MARKED
2096 flags. Fortunately we know the covariancy is valid (it
2097 has already been checked), so we can just iterate along
2098 the binfos, which have been chained in inheritance graph
2099 order. Of course it is lame that we have to repeat the
2100 search here anyway -- we should really be caching pieces
2101 of the vtable and avoiding this repeated work. */
2102 tree thunk_binfo, base_binfo;
2104 /* Find the base binfo within the overriding function's
2105 return type. We will always find a thunk_binfo, except
2106 when the covariancy is invalid (which we will have
2107 already diagnosed). */
2108 for (base_binfo = TYPE_BINFO (base_return),
2109 thunk_binfo = TYPE_BINFO (over_return);
2111 thunk_binfo = TREE_CHAIN (thunk_binfo))
2112 if (SAME_BINFO_TYPE_P (BINFO_TYPE (thunk_binfo),
2113 BINFO_TYPE (base_binfo)))
2116 /* See if virtual inheritance is involved. */
2117 for (virtual_offset = thunk_binfo;
2119 virtual_offset = BINFO_INHERITANCE_CHAIN (virtual_offset))
2120 if (BINFO_VIRTUAL_P (virtual_offset))
2124 || (thunk_binfo && !BINFO_OFFSET_ZEROP (thunk_binfo)))
2126 tree offset = convert (ssizetype, BINFO_OFFSET (thunk_binfo));
2130 /* We convert via virtual base. Adjust the fixed
2131 offset to be from there. */
2132 offset = size_diffop
2134 (ssizetype, BINFO_OFFSET (virtual_offset)));
2137 /* There was an existing fixed offset, this must be
2138 from the base just converted to, and the base the
2139 FN was thunking to. */
2140 fixed_offset = size_binop (PLUS_EXPR, fixed_offset, offset);
2142 fixed_offset = offset;
2146 if (fixed_offset || virtual_offset)
2147 /* Replace the overriding function with a covariant thunk. We
2148 will emit the overriding function in its own slot as
2150 overrider_fn = make_thunk (overrider_target, /*this_adjusting=*/0,
2151 fixed_offset, virtual_offset);
2154 gcc_assert (DECL_INVALID_OVERRIDER_P (overrider_target) ||
2155 !DECL_THUNK_P (fn));
2157 /* Assume that we will produce a thunk that convert all the way to
2158 the final overrider, and not to an intermediate virtual base. */
2159 virtual_base = NULL_TREE;
2161 /* See if we can convert to an intermediate virtual base first, and then
2162 use the vcall offset located there to finish the conversion. */
2163 for (; b; b = BINFO_INHERITANCE_CHAIN (b))
2165 /* If we find the final overrider, then we can stop
2167 if (SAME_BINFO_TYPE_P (BINFO_TYPE (b),
2168 BINFO_TYPE (TREE_VALUE (overrider))))
2171 /* If we find a virtual base, and we haven't yet found the
2172 overrider, then there is a virtual base between the
2173 declaring base (first_defn) and the final overrider. */
2174 if (BINFO_VIRTUAL_P (b))
2181 if (overrider_fn != overrider_target && !virtual_base)
2183 /* The ABI specifies that a covariant thunk includes a mangling
2184 for a this pointer adjustment. This-adjusting thunks that
2185 override a function from a virtual base have a vcall
2186 adjustment. When the virtual base in question is a primary
2187 virtual base, we know the adjustments are zero, (and in the
2188 non-covariant case, we would not use the thunk).
2189 Unfortunately we didn't notice this could happen, when
2190 designing the ABI and so never mandated that such a covariant
2191 thunk should be emitted. Because we must use the ABI mandated
2192 name, we must continue searching from the binfo where we
2193 found the most recent definition of the function, towards the
2194 primary binfo which first introduced the function into the
2195 vtable. If that enters a virtual base, we must use a vcall
2196 this-adjusting thunk. Bleah! */
2197 tree probe = first_defn;
2199 while ((probe = get_primary_binfo (probe))
2200 && (unsigned) list_length (BINFO_VIRTUALS (probe)) > ix)
2201 if (BINFO_VIRTUAL_P (probe))
2202 virtual_base = probe;
2205 /* Even if we find a virtual base, the correct delta is
2206 between the overrider and the binfo we're building a vtable
2208 goto virtual_covariant;
2211 /* Compute the constant adjustment to the `this' pointer. The
2212 `this' pointer, when this function is called, will point at BINFO
2213 (or one of its primary bases, which are at the same offset). */
2215 /* The `this' pointer needs to be adjusted from the declaration to
2216 the nearest virtual base. */
2217 delta = size_diffop (convert (ssizetype, BINFO_OFFSET (virtual_base)),
2218 convert (ssizetype, BINFO_OFFSET (first_defn)));
2220 /* If the nearest definition is in a lost primary, we don't need an
2221 entry in our vtable. Except possibly in a constructor vtable,
2222 if we happen to get our primary back. In that case, the offset
2223 will be zero, as it will be a primary base. */
2224 delta = size_zero_node;
2226 /* The `this' pointer needs to be adjusted from pointing to
2227 BINFO to pointing at the base where the final overrider
2230 delta = size_diffop (convert (ssizetype,
2231 BINFO_OFFSET (TREE_VALUE (overrider))),
2232 convert (ssizetype, BINFO_OFFSET (binfo)));
2234 modify_vtable_entry (t, binfo, overrider_fn, delta, virtuals);
2237 BV_VCALL_INDEX (*virtuals)
2238 = get_vcall_index (overrider_target, BINFO_TYPE (virtual_base));
2240 BV_VCALL_INDEX (*virtuals) = NULL_TREE;
2243 /* Called from modify_all_vtables via dfs_walk. */
2246 dfs_modify_vtables (tree binfo, void* data)
2248 tree t = (tree) data;
2253 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
2254 /* A base without a vtable needs no modification, and its bases
2255 are uninteresting. */
2256 return dfs_skip_bases;
2258 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t)
2259 && !CLASSTYPE_HAS_PRIMARY_BASE_P (t))
2260 /* Don't do the primary vtable, if it's new. */
2263 if (BINFO_PRIMARY_P (binfo) && !BINFO_VIRTUAL_P (binfo))
2264 /* There's no need to modify the vtable for a non-virtual primary
2265 base; we're not going to use that vtable anyhow. We do still
2266 need to do this for virtual primary bases, as they could become
2267 non-primary in a construction vtable. */
2270 make_new_vtable (t, binfo);
2272 /* Now, go through each of the virtual functions in the virtual
2273 function table for BINFO. Find the final overrider, and update
2274 the BINFO_VIRTUALS list appropriately. */
2275 for (ix = 0, virtuals = BINFO_VIRTUALS (binfo),
2276 old_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
2278 ix++, virtuals = TREE_CHAIN (virtuals),
2279 old_virtuals = TREE_CHAIN (old_virtuals))
2280 update_vtable_entry_for_fn (t,
2282 BV_FN (old_virtuals),
2288 /* Update all of the primary and secondary vtables for T. Create new
2289 vtables as required, and initialize their RTTI information. Each
2290 of the functions in VIRTUALS is declared in T and may override a
2291 virtual function from a base class; find and modify the appropriate
2292 entries to point to the overriding functions. Returns a list, in
2293 declaration order, of the virtual functions that are declared in T,
2294 but do not appear in the primary base class vtable, and which
2295 should therefore be appended to the end of the vtable for T. */
2298 modify_all_vtables (tree t, tree virtuals)
2300 tree binfo = TYPE_BINFO (t);
2303 /* Update all of the vtables. */
2304 dfs_walk_once (binfo, dfs_modify_vtables, NULL, t);
2306 /* Add virtual functions not already in our primary vtable. These
2307 will be both those introduced by this class, and those overridden
2308 from secondary bases. It does not include virtuals merely
2309 inherited from secondary bases. */
2310 for (fnsp = &virtuals; *fnsp; )
2312 tree fn = TREE_VALUE (*fnsp);
2314 if (!value_member (fn, BINFO_VIRTUALS (binfo))
2315 || DECL_VINDEX (fn) == error_mark_node)
2317 /* We don't need to adjust the `this' pointer when
2318 calling this function. */
2319 BV_DELTA (*fnsp) = integer_zero_node;
2320 BV_VCALL_INDEX (*fnsp) = NULL_TREE;
2322 /* This is a function not already in our vtable. Keep it. */
2323 fnsp = &TREE_CHAIN (*fnsp);
2326 /* We've already got an entry for this function. Skip it. */
2327 *fnsp = TREE_CHAIN (*fnsp);
2333 /* Get the base virtual function declarations in T that have the
2337 get_basefndecls (tree name, tree t)
2340 tree base_fndecls = NULL_TREE;
2341 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
2344 /* Find virtual functions in T with the indicated NAME. */
2345 i = lookup_fnfields_1 (t, name);
2347 for (methods = VEC_index (tree, CLASSTYPE_METHOD_VEC (t), i);
2349 methods = OVL_NEXT (methods))
2351 tree method = OVL_CURRENT (methods);
2353 if (TREE_CODE (method) == FUNCTION_DECL
2354 && DECL_VINDEX (method))
2355 base_fndecls = tree_cons (NULL_TREE, method, base_fndecls);
2359 return base_fndecls;
2361 for (i = 0; i < n_baseclasses; i++)
2363 tree basetype = BINFO_TYPE (BINFO_BASE_BINFO (TYPE_BINFO (t), i));
2364 base_fndecls = chainon (get_basefndecls (name, basetype),
2368 return base_fndecls;
2371 /* If this declaration supersedes the declaration of
2372 a method declared virtual in the base class, then
2373 mark this field as being virtual as well. */
2376 check_for_override (tree decl, tree ctype)
2378 if (TREE_CODE (decl) == TEMPLATE_DECL)
2379 /* In [temp.mem] we have:
2381 A specialization of a member function template does not
2382 override a virtual function from a base class. */
2384 if ((DECL_DESTRUCTOR_P (decl)
2385 || IDENTIFIER_VIRTUAL_P (DECL_NAME (decl))
2386 || DECL_CONV_FN_P (decl))
2387 && look_for_overrides (ctype, decl)
2388 && !DECL_STATIC_FUNCTION_P (decl))
2389 /* Set DECL_VINDEX to a value that is neither an INTEGER_CST nor
2390 the error_mark_node so that we know it is an overriding
2392 DECL_VINDEX (decl) = decl;
2394 if (DECL_VIRTUAL_P (decl))
2396 if (!DECL_VINDEX (decl))
2397 DECL_VINDEX (decl) = error_mark_node;
2398 IDENTIFIER_VIRTUAL_P (DECL_NAME (decl)) = 1;
2402 /* Warn about hidden virtual functions that are not overridden in t.
2403 We know that constructors and destructors don't apply. */
2406 warn_hidden (tree t)
2408 VEC(tree,gc) *method_vec = CLASSTYPE_METHOD_VEC (t);
2412 /* We go through each separately named virtual function. */
2413 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2414 VEC_iterate (tree, method_vec, i, fns);
2425 /* All functions in this slot in the CLASSTYPE_METHOD_VEC will
2426 have the same name. Figure out what name that is. */
2427 name = DECL_NAME (OVL_CURRENT (fns));
2428 /* There are no possibly hidden functions yet. */
2429 base_fndecls = NULL_TREE;
2430 /* Iterate through all of the base classes looking for possibly
2431 hidden functions. */
2432 for (binfo = TYPE_BINFO (t), j = 0;
2433 BINFO_BASE_ITERATE (binfo, j, base_binfo); j++)
2435 tree basetype = BINFO_TYPE (base_binfo);
2436 base_fndecls = chainon (get_basefndecls (name, basetype),
2440 /* If there are no functions to hide, continue. */
2444 /* Remove any overridden functions. */
2445 for (fn = fns; fn; fn = OVL_NEXT (fn))
2447 fndecl = OVL_CURRENT (fn);
2448 if (DECL_VINDEX (fndecl))
2450 tree *prev = &base_fndecls;
2453 /* If the method from the base class has the same
2454 signature as the method from the derived class, it
2455 has been overridden. */
2456 if (same_signature_p (fndecl, TREE_VALUE (*prev)))
2457 *prev = TREE_CHAIN (*prev);
2459 prev = &TREE_CHAIN (*prev);
2463 /* Now give a warning for all base functions without overriders,
2464 as they are hidden. */
2465 while (base_fndecls)
2467 /* Here we know it is a hider, and no overrider exists. */
2468 warning (OPT_Woverloaded_virtual, "%q+D was hidden", TREE_VALUE (base_fndecls));
2469 warning (OPT_Woverloaded_virtual, " by %q+D", fns);
2470 base_fndecls = TREE_CHAIN (base_fndecls);
2475 /* Check for things that are invalid. There are probably plenty of other
2476 things we should check for also. */
2479 finish_struct_anon (tree t)
2483 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
2485 if (TREE_STATIC (field))
2487 if (TREE_CODE (field) != FIELD_DECL)
2490 if (DECL_NAME (field) == NULL_TREE
2491 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
2493 bool is_union = TREE_CODE (TREE_TYPE (field)) == UNION_TYPE;
2494 tree elt = TYPE_FIELDS (TREE_TYPE (field));
2495 for (; elt; elt = TREE_CHAIN (elt))
2497 /* We're generally only interested in entities the user
2498 declared, but we also find nested classes by noticing
2499 the TYPE_DECL that we create implicitly. You're
2500 allowed to put one anonymous union inside another,
2501 though, so we explicitly tolerate that. We use
2502 TYPE_ANONYMOUS_P rather than ANON_AGGR_TYPE_P so that
2503 we also allow unnamed types used for defining fields. */
2504 if (DECL_ARTIFICIAL (elt)
2505 && (!DECL_IMPLICIT_TYPEDEF_P (elt)
2506 || TYPE_ANONYMOUS_P (TREE_TYPE (elt))))
2509 if (TREE_CODE (elt) != FIELD_DECL)
2512 permerror (input_location, "%q+#D invalid; an anonymous union can "
2513 "only have non-static data members", elt);
2515 permerror (input_location, "%q+#D invalid; an anonymous struct can "
2516 "only have non-static data members", elt);
2520 if (TREE_PRIVATE (elt))
2523 permerror (input_location, "private member %q+#D in anonymous union", elt);
2525 permerror (input_location, "private member %q+#D in anonymous struct", elt);
2527 else if (TREE_PROTECTED (elt))
2530 permerror (input_location, "protected member %q+#D in anonymous union", elt);
2532 permerror (input_location, "protected member %q+#D in anonymous struct", elt);
2535 TREE_PRIVATE (elt) = TREE_PRIVATE (field);
2536 TREE_PROTECTED (elt) = TREE_PROTECTED (field);
2542 /* Add T to CLASSTYPE_DECL_LIST of current_class_type which
2543 will be used later during class template instantiation.
2544 When FRIEND_P is zero, T can be a static member data (VAR_DECL),
2545 a non-static member data (FIELD_DECL), a member function
2546 (FUNCTION_DECL), a nested type (RECORD_TYPE, ENUM_TYPE),
2547 a typedef (TYPE_DECL) or a member class template (TEMPLATE_DECL)
2548 When FRIEND_P is nonzero, T is either a friend class
2549 (RECORD_TYPE, TEMPLATE_DECL) or a friend function
2550 (FUNCTION_DECL, TEMPLATE_DECL). */
2553 maybe_add_class_template_decl_list (tree type, tree t, int friend_p)
2555 /* Save some memory by not creating TREE_LIST if TYPE is not template. */
2556 if (CLASSTYPE_TEMPLATE_INFO (type))
2557 CLASSTYPE_DECL_LIST (type)
2558 = tree_cons (friend_p ? NULL_TREE : type,
2559 t, CLASSTYPE_DECL_LIST (type));
2562 /* Create default constructors, assignment operators, and so forth for
2563 the type indicated by T, if they are needed. CANT_HAVE_CONST_CTOR,
2564 and CANT_HAVE_CONST_ASSIGNMENT are nonzero if, for whatever reason,
2565 the class cannot have a default constructor, copy constructor
2566 taking a const reference argument, or an assignment operator taking
2567 a const reference, respectively. */
2570 add_implicitly_declared_members (tree t,
2571 int cant_have_const_cctor,
2572 int cant_have_const_assignment)
2575 if (!CLASSTYPE_DESTRUCTORS (t))
2577 /* In general, we create destructors lazily. */
2578 CLASSTYPE_LAZY_DESTRUCTOR (t) = 1;
2579 /* However, if the implicit destructor is non-trivial
2580 destructor, we sometimes have to create it at this point. */
2581 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t))
2585 if (TYPE_FOR_JAVA (t))
2586 /* If this a Java class, any non-trivial destructor is
2587 invalid, even if compiler-generated. Therefore, if the
2588 destructor is non-trivial we create it now. */
2596 /* If the implicit destructor will be virtual, then we must
2597 generate it now because (unfortunately) we do not
2598 generate virtual tables lazily. */
2599 binfo = TYPE_BINFO (t);
2600 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
2605 base_type = BINFO_TYPE (base_binfo);
2606 dtor = CLASSTYPE_DESTRUCTORS (base_type);
2607 if (dtor && DECL_VIRTUAL_P (dtor))
2615 /* If we can't get away with being lazy, generate the destructor
2618 lazily_declare_fn (sfk_destructor, t);
2624 If there is no user-declared constructor for a class, a default
2625 constructor is implicitly declared. */
2626 if (! TYPE_HAS_USER_CONSTRUCTOR (t))
2628 TYPE_HAS_DEFAULT_CONSTRUCTOR (t) = 1;
2629 CLASSTYPE_LAZY_DEFAULT_CTOR (t) = 1;
2634 If a class definition does not explicitly declare a copy
2635 constructor, one is declared implicitly. */
2636 if (! TYPE_HAS_INIT_REF (t) && ! TYPE_FOR_JAVA (t))
2638 TYPE_HAS_INIT_REF (t) = 1;
2639 TYPE_HAS_CONST_INIT_REF (t) = !cant_have_const_cctor;
2640 CLASSTYPE_LAZY_COPY_CTOR (t) = 1;
2643 /* If there is no assignment operator, one will be created if and
2644 when it is needed. For now, just record whether or not the type
2645 of the parameter to the assignment operator will be a const or
2646 non-const reference. */
2647 if (!TYPE_HAS_ASSIGN_REF (t) && !TYPE_FOR_JAVA (t))
2649 TYPE_HAS_ASSIGN_REF (t) = 1;
2650 TYPE_HAS_CONST_ASSIGN_REF (t) = !cant_have_const_assignment;
2651 CLASSTYPE_LAZY_ASSIGNMENT_OP (t) = 1;
2655 /* Subroutine of finish_struct_1. Recursively count the number of fields
2656 in TYPE, including anonymous union members. */
2659 count_fields (tree fields)
2663 for (x = fields; x; x = TREE_CHAIN (x))
2665 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2666 n_fields += count_fields (TYPE_FIELDS (TREE_TYPE (x)));
2673 /* Subroutine of finish_struct_1. Recursively add all the fields in the
2674 TREE_LIST FIELDS to the SORTED_FIELDS_TYPE elts, starting at offset IDX. */
2677 add_fields_to_record_type (tree fields, struct sorted_fields_type *field_vec, int idx)
2680 for (x = fields; x; x = TREE_CHAIN (x))
2682 if (TREE_CODE (x) == FIELD_DECL && ANON_AGGR_TYPE_P (TREE_TYPE (x)))
2683 idx = add_fields_to_record_type (TYPE_FIELDS (TREE_TYPE (x)), field_vec, idx);
2685 field_vec->elts[idx++] = x;
2690 /* FIELD is a bit-field. We are finishing the processing for its
2691 enclosing type. Issue any appropriate messages and set appropriate
2692 flags. Returns false if an error has been diagnosed. */
2695 check_bitfield_decl (tree field)
2697 tree type = TREE_TYPE (field);
2700 /* Extract the declared width of the bitfield, which has been
2701 temporarily stashed in DECL_INITIAL. */
2702 w = DECL_INITIAL (field);
2703 gcc_assert (w != NULL_TREE);
2704 /* Remove the bit-field width indicator so that the rest of the
2705 compiler does not treat that value as an initializer. */
2706 DECL_INITIAL (field) = NULL_TREE;
2708 /* Detect invalid bit-field type. */
2709 if (!INTEGRAL_TYPE_P (type))
2711 error ("bit-field %q+#D with non-integral type", field);
2712 w = error_mark_node;
2716 /* Avoid the non_lvalue wrapper added by fold for PLUS_EXPRs. */
2719 /* detect invalid field size. */
2720 w = integral_constant_value (w);
2722 if (TREE_CODE (w) != INTEGER_CST)
2724 error ("bit-field %q+D width not an integer constant", field);
2725 w = error_mark_node;
2727 else if (tree_int_cst_sgn (w) < 0)
2729 error ("negative width in bit-field %q+D", field);
2730 w = error_mark_node;
2732 else if (integer_zerop (w) && DECL_NAME (field) != 0)
2734 error ("zero width for bit-field %q+D", field);
2735 w = error_mark_node;
2737 else if (compare_tree_int (w, TYPE_PRECISION (type)) > 0
2738 && TREE_CODE (type) != ENUMERAL_TYPE
2739 && TREE_CODE (type) != BOOLEAN_TYPE)
2740 warning (0, "width of %q+D exceeds its type", field);
2741 else if (TREE_CODE (type) == ENUMERAL_TYPE
2742 && (0 > compare_tree_int (w,
2743 tree_int_cst_min_precision
2744 (TYPE_MIN_VALUE (type),
2745 TYPE_UNSIGNED (type)))
2746 || 0 > compare_tree_int (w,
2747 tree_int_cst_min_precision
2748 (TYPE_MAX_VALUE (type),
2749 TYPE_UNSIGNED (type)))))
2750 warning (0, "%q+D is too small to hold all values of %q#T", field, type);
2753 if (w != error_mark_node)
2755 DECL_SIZE (field) = convert (bitsizetype, w);
2756 DECL_BIT_FIELD (field) = 1;
2761 /* Non-bit-fields are aligned for their type. */
2762 DECL_BIT_FIELD (field) = 0;
2763 CLEAR_DECL_C_BIT_FIELD (field);
2768 /* FIELD is a non bit-field. We are finishing the processing for its
2769 enclosing type T. Issue any appropriate messages and set appropriate
2773 check_field_decl (tree field,
2775 int* cant_have_const_ctor,
2776 int* no_const_asn_ref,
2777 int* any_default_members)
2779 tree type = strip_array_types (TREE_TYPE (field));
2781 /* An anonymous union cannot contain any fields which would change
2782 the settings of CANT_HAVE_CONST_CTOR and friends. */
2783 if (ANON_UNION_TYPE_P (type))
2785 /* And, we don't set TYPE_HAS_CONST_INIT_REF, etc., for anonymous
2786 structs. So, we recurse through their fields here. */
2787 else if (ANON_AGGR_TYPE_P (type))
2791 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2792 if (TREE_CODE (fields) == FIELD_DECL && !DECL_C_BIT_FIELD (field))
2793 check_field_decl (fields, t, cant_have_const_ctor,
2794 no_const_asn_ref, any_default_members);
2796 /* Check members with class type for constructors, destructors,
2798 else if (CLASS_TYPE_P (type))
2800 /* Never let anything with uninheritable virtuals
2801 make it through without complaint. */
2802 abstract_virtuals_error (field, type);
2804 if (TREE_CODE (t) == UNION_TYPE)
2806 if (TYPE_NEEDS_CONSTRUCTING (type))
2807 error ("member %q+#D with constructor not allowed in union",
2809 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
2810 error ("member %q+#D with destructor not allowed in union", field);
2811 if (TYPE_HAS_COMPLEX_ASSIGN_REF (type))
2812 error ("member %q+#D with copy assignment operator not allowed in union",
2817 TYPE_NEEDS_CONSTRUCTING (t) |= TYPE_NEEDS_CONSTRUCTING (type);
2818 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
2819 |= TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type);
2820 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_HAS_COMPLEX_ASSIGN_REF (type);
2821 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_HAS_COMPLEX_INIT_REF (type);
2822 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_HAS_COMPLEX_DFLT (type);
2825 if (!TYPE_HAS_CONST_INIT_REF (type))
2826 *cant_have_const_ctor = 1;
2828 if (!TYPE_HAS_CONST_ASSIGN_REF (type))
2829 *no_const_asn_ref = 1;
2831 if (DECL_INITIAL (field) != NULL_TREE)
2833 /* `build_class_init_list' does not recognize
2835 if (TREE_CODE (t) == UNION_TYPE && any_default_members != 0)
2836 error ("multiple fields in union %qT initialized", t);
2837 *any_default_members = 1;
2841 /* Check the data members (both static and non-static), class-scoped
2842 typedefs, etc., appearing in the declaration of T. Issue
2843 appropriate diagnostics. Sets ACCESS_DECLS to a list (in
2844 declaration order) of access declarations; each TREE_VALUE in this
2845 list is a USING_DECL.
2847 In addition, set the following flags:
2850 The class is empty, i.e., contains no non-static data members.
2852 CANT_HAVE_CONST_CTOR_P
2853 This class cannot have an implicitly generated copy constructor
2854 taking a const reference.
2856 CANT_HAVE_CONST_ASN_REF
2857 This class cannot have an implicitly generated assignment
2858 operator taking a const reference.
2860 All of these flags should be initialized before calling this
2863 Returns a pointer to the end of the TYPE_FIELDs chain; additional
2864 fields can be added by adding to this chain. */
2867 check_field_decls (tree t, tree *access_decls,
2868 int *cant_have_const_ctor_p,
2869 int *no_const_asn_ref_p)
2874 int any_default_members;
2877 /* Assume there are no access declarations. */
2878 *access_decls = NULL_TREE;
2879 /* Assume this class has no pointer members. */
2880 has_pointers = false;
2881 /* Assume none of the members of this class have default
2883 any_default_members = 0;
2885 for (field = &TYPE_FIELDS (t); *field; field = next)
2888 tree type = TREE_TYPE (x);
2890 next = &TREE_CHAIN (x);
2892 if (TREE_CODE (x) == USING_DECL)
2894 /* Prune the access declaration from the list of fields. */
2895 *field = TREE_CHAIN (x);
2897 /* Save the access declarations for our caller. */
2898 *access_decls = tree_cons (NULL_TREE, x, *access_decls);
2900 /* Since we've reset *FIELD there's no reason to skip to the
2906 if (TREE_CODE (x) == TYPE_DECL
2907 || TREE_CODE (x) == TEMPLATE_DECL)
2910 /* If we've gotten this far, it's a data member, possibly static,
2911 or an enumerator. */
2912 DECL_CONTEXT (x) = t;
2914 /* When this goes into scope, it will be a non-local reference. */
2915 DECL_NONLOCAL (x) = 1;
2917 if (TREE_CODE (t) == UNION_TYPE)
2921 If a union contains a static data member, or a member of
2922 reference type, the program is ill-formed. */
2923 if (TREE_CODE (x) == VAR_DECL)
2925 error ("%q+D may not be static because it is a member of a union", x);
2928 if (TREE_CODE (type) == REFERENCE_TYPE)
2930 error ("%q+D may not have reference type %qT because"
2931 " it is a member of a union",
2937 /* Perform error checking that did not get done in
2939 if (TREE_CODE (type) == FUNCTION_TYPE)
2941 error ("field %q+D invalidly declared function type", x);
2942 type = build_pointer_type (type);
2943 TREE_TYPE (x) = type;
2945 else if (TREE_CODE (type) == METHOD_TYPE)
2947 error ("field %q+D invalidly declared method type", x);
2948 type = build_pointer_type (type);
2949 TREE_TYPE (x) = type;
2952 if (type == error_mark_node)
2955 if (TREE_CODE (x) == CONST_DECL || TREE_CODE (x) == VAR_DECL)
2958 /* Now it can only be a FIELD_DECL. */
2960 if (TREE_PRIVATE (x) || TREE_PROTECTED (x))
2961 CLASSTYPE_NON_AGGREGATE (t) = 1;
2963 /* If this is of reference type, check if it needs an init. */
2964 if (TREE_CODE (type) == REFERENCE_TYPE)
2966 CLASSTYPE_NON_POD_P (t) = 1;
2967 if (DECL_INITIAL (x) == NULL_TREE)
2968 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
2970 /* ARM $12.6.2: [A member initializer list] (or, for an
2971 aggregate, initialization by a brace-enclosed list) is the
2972 only way to initialize nonstatic const and reference
2974 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
2977 type = strip_array_types (type);
2979 if (TYPE_PACKED (t))
2981 if (!pod_type_p (type) && !TYPE_PACKED (type))
2985 "ignoring packed attribute because of unpacked non-POD field %q+#D",
2989 else if (DECL_C_BIT_FIELD (x)
2990 || TYPE_ALIGN (TREE_TYPE (x)) > BITS_PER_UNIT)
2991 DECL_PACKED (x) = 1;
2994 if (DECL_C_BIT_FIELD (x) && integer_zerop (DECL_INITIAL (x)))
2995 /* We don't treat zero-width bitfields as making a class
3000 /* The class is non-empty. */
3001 CLASSTYPE_EMPTY_P (t) = 0;
3002 /* The class is not even nearly empty. */
3003 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3004 /* If one of the data members contains an empty class,
3006 if (CLASS_TYPE_P (type)
3007 && CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3008 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
3011 /* This is used by -Weffc++ (see below). Warn only for pointers
3012 to members which might hold dynamic memory. So do not warn
3013 for pointers to functions or pointers to members. */
3014 if (TYPE_PTR_P (type)
3015 && !TYPE_PTRFN_P (type)
3016 && !TYPE_PTR_TO_MEMBER_P (type))
3017 has_pointers = true;
3019 if (CLASS_TYPE_P (type))
3021 if (CLASSTYPE_REF_FIELDS_NEED_INIT (type))
3022 SET_CLASSTYPE_REF_FIELDS_NEED_INIT (t, 1);
3023 if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (type))
3024 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3027 if (DECL_MUTABLE_P (x) || TYPE_HAS_MUTABLE_P (type))
3028 CLASSTYPE_HAS_MUTABLE (t) = 1;
3030 if (! pod_type_p (type))
3031 /* DR 148 now allows pointers to members (which are POD themselves),
3032 to be allowed in POD structs. */
3033 CLASSTYPE_NON_POD_P (t) = 1;
3035 if (! zero_init_p (type))
3036 CLASSTYPE_NON_ZERO_INIT_P (t) = 1;
3038 /* If any field is const, the structure type is pseudo-const. */
3039 if (CP_TYPE_CONST_P (type))
3041 C_TYPE_FIELDS_READONLY (t) = 1;
3042 if (DECL_INITIAL (x) == NULL_TREE)
3043 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t, 1);
3045 /* ARM $12.6.2: [A member initializer list] (or, for an
3046 aggregate, initialization by a brace-enclosed list) is the
3047 only way to initialize nonstatic const and reference
3049 TYPE_HAS_COMPLEX_ASSIGN_REF (t) = 1;
3051 /* A field that is pseudo-const makes the structure likewise. */
3052 else if (CLASS_TYPE_P (type))
3054 C_TYPE_FIELDS_READONLY (t) |= C_TYPE_FIELDS_READONLY (type);
3055 SET_CLASSTYPE_READONLY_FIELDS_NEED_INIT (t,
3056 CLASSTYPE_READONLY_FIELDS_NEED_INIT (t)
3057 | CLASSTYPE_READONLY_FIELDS_NEED_INIT (type));
3060 /* Core issue 80: A nonstatic data member is required to have a
3061 different name from the class iff the class has a
3062 user-declared constructor. */
3063 if (constructor_name_p (DECL_NAME (x), t)
3064 && TYPE_HAS_USER_CONSTRUCTOR (t))
3065 permerror (input_location, "field %q+#D with same name as class", x);
3067 /* We set DECL_C_BIT_FIELD in grokbitfield.
3068 If the type and width are valid, we'll also set DECL_BIT_FIELD. */
3069 if (! DECL_C_BIT_FIELD (x) || ! check_bitfield_decl (x))
3070 check_field_decl (x, t,
3071 cant_have_const_ctor_p,
3073 &any_default_members);
3076 /* Effective C++ rule 11: if a class has dynamic memory held by pointers,
3077 it should also define a copy constructor and an assignment operator to
3078 implement the correct copy semantic (deep vs shallow, etc.). As it is
3079 not feasible to check whether the constructors do allocate dynamic memory
3080 and store it within members, we approximate the warning like this:
3082 -- Warn only if there are members which are pointers
3083 -- Warn only if there is a non-trivial constructor (otherwise,
3084 there cannot be memory allocated).
3085 -- Warn only if there is a non-trivial destructor. We assume that the
3086 user at least implemented the cleanup correctly, and a destructor
3087 is needed to free dynamic memory.
3089 This seems enough for practical purposes. */
3092 && TYPE_HAS_USER_CONSTRUCTOR (t)
3093 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t)
3094 && !(TYPE_HAS_INIT_REF (t) && TYPE_HAS_ASSIGN_REF (t)))
3096 warning (OPT_Weffc__, "%q#T has pointer data members", t);
3098 if (! TYPE_HAS_INIT_REF (t))
3100 warning (OPT_Weffc__,
3101 " but does not override %<%T(const %T&)%>", t, t);
3102 if (!TYPE_HAS_ASSIGN_REF (t))
3103 warning (OPT_Weffc__, " or %<operator=(const %T&)%>", t);
3105 else if (! TYPE_HAS_ASSIGN_REF (t))
3106 warning (OPT_Weffc__,
3107 " but does not override %<operator=(const %T&)%>", t);
3110 /* If any of the fields couldn't be packed, unset TYPE_PACKED. */
3112 TYPE_PACKED (t) = 0;
3114 /* Check anonymous struct/anonymous union fields. */
3115 finish_struct_anon (t);
3117 /* We've built up the list of access declarations in reverse order.
3119 *access_decls = nreverse (*access_decls);
3122 /* If TYPE is an empty class type, records its OFFSET in the table of
3126 record_subobject_offset (tree type, tree offset, splay_tree offsets)
3130 if (!is_empty_class (type))
3133 /* Record the location of this empty object in OFFSETS. */
3134 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3136 n = splay_tree_insert (offsets,
3137 (splay_tree_key) offset,
3138 (splay_tree_value) NULL_TREE);
3139 n->value = ((splay_tree_value)
3140 tree_cons (NULL_TREE,
3147 /* Returns nonzero if TYPE is an empty class type and there is
3148 already an entry in OFFSETS for the same TYPE as the same OFFSET. */
3151 check_subobject_offset (tree type, tree offset, splay_tree offsets)
3156 if (!is_empty_class (type))
3159 /* Record the location of this empty object in OFFSETS. */
3160 n = splay_tree_lookup (offsets, (splay_tree_key) offset);
3164 for (t = (tree) n->value; t; t = TREE_CHAIN (t))
3165 if (same_type_p (TREE_VALUE (t), type))
3171 /* Walk through all the subobjects of TYPE (located at OFFSET). Call
3172 F for every subobject, passing it the type, offset, and table of
3173 OFFSETS. If VBASES_P is one, then virtual non-primary bases should
3176 If MAX_OFFSET is non-NULL, then subobjects with an offset greater
3177 than MAX_OFFSET will not be walked.
3179 If F returns a nonzero value, the traversal ceases, and that value
3180 is returned. Otherwise, returns zero. */
3183 walk_subobject_offsets (tree type,
3184 subobject_offset_fn f,
3191 tree type_binfo = NULL_TREE;
3193 /* If this OFFSET is bigger than the MAX_OFFSET, then we should
3195 if (max_offset && INT_CST_LT (max_offset, offset))
3198 if (type == error_mark_node)
3203 if (abi_version_at_least (2))
3205 type = BINFO_TYPE (type);
3208 if (CLASS_TYPE_P (type))
3214 /* Avoid recursing into objects that are not interesting. */
3215 if (!CLASSTYPE_CONTAINS_EMPTY_CLASS_P (type))
3218 /* Record the location of TYPE. */
3219 r = (*f) (type, offset, offsets);
3223 /* Iterate through the direct base classes of TYPE. */
3225 type_binfo = TYPE_BINFO (type);
3226 for (i = 0; BINFO_BASE_ITERATE (type_binfo, i, binfo); i++)
3230 if (abi_version_at_least (2)
3231 && BINFO_VIRTUAL_P (binfo))
3235 && BINFO_VIRTUAL_P (binfo)
3236 && !BINFO_PRIMARY_P (binfo))
3239 if (!abi_version_at_least (2))
3240 binfo_offset = size_binop (PLUS_EXPR,
3242 BINFO_OFFSET (binfo));
3246 /* We cannot rely on BINFO_OFFSET being set for the base
3247 class yet, but the offsets for direct non-virtual
3248 bases can be calculated by going back to the TYPE. */
3249 orig_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), i);
3250 binfo_offset = size_binop (PLUS_EXPR,
3252 BINFO_OFFSET (orig_binfo));
3255 r = walk_subobject_offsets (binfo,
3260 (abi_version_at_least (2)
3261 ? /*vbases_p=*/0 : vbases_p));
3266 if (abi_version_at_least (2) && CLASSTYPE_VBASECLASSES (type))
3269 VEC(tree,gc) *vbases;
3271 /* Iterate through the virtual base classes of TYPE. In G++
3272 3.2, we included virtual bases in the direct base class
3273 loop above, which results in incorrect results; the
3274 correct offsets for virtual bases are only known when
3275 working with the most derived type. */
3277 for (vbases = CLASSTYPE_VBASECLASSES (type), ix = 0;
3278 VEC_iterate (tree, vbases, ix, binfo); ix++)
3280 r = walk_subobject_offsets (binfo,
3282 size_binop (PLUS_EXPR,
3284 BINFO_OFFSET (binfo)),
3293 /* We still have to walk the primary base, if it is
3294 virtual. (If it is non-virtual, then it was walked
3296 tree vbase = get_primary_binfo (type_binfo);
3298 if (vbase && BINFO_VIRTUAL_P (vbase)
3299 && BINFO_PRIMARY_P (vbase)
3300 && BINFO_INHERITANCE_CHAIN (vbase) == type_binfo)
3302 r = (walk_subobject_offsets
3304 offsets, max_offset, /*vbases_p=*/0));
3311 /* Iterate through the fields of TYPE. */
3312 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
3313 if (TREE_CODE (field) == FIELD_DECL && !DECL_ARTIFICIAL (field))
3317 if (abi_version_at_least (2))
3318 field_offset = byte_position (field);
3320 /* In G++ 3.2, DECL_FIELD_OFFSET was used. */
3321 field_offset = DECL_FIELD_OFFSET (field);
3323 r = walk_subobject_offsets (TREE_TYPE (field),
3325 size_binop (PLUS_EXPR,
3335 else if (TREE_CODE (type) == ARRAY_TYPE)
3337 tree element_type = strip_array_types (type);
3338 tree domain = TYPE_DOMAIN (type);
3341 /* Avoid recursing into objects that are not interesting. */
3342 if (!CLASS_TYPE_P (element_type)
3343 || !CLASSTYPE_CONTAINS_EMPTY_CLASS_P (element_type))
3346 /* Step through each of the elements in the array. */
3347 for (index = size_zero_node;
3348 /* G++ 3.2 had an off-by-one error here. */
3349 (abi_version_at_least (2)
3350 ? !INT_CST_LT (TYPE_MAX_VALUE (domain), index)
3351 : INT_CST_LT (index, TYPE_MAX_VALUE (domain)));
3352 index = size_binop (PLUS_EXPR, index, size_one_node))
3354 r = walk_subobject_offsets (TREE_TYPE (type),
3362 offset = size_binop (PLUS_EXPR, offset,
3363 TYPE_SIZE_UNIT (TREE_TYPE (type)));
3364 /* If this new OFFSET is bigger than the MAX_OFFSET, then
3365 there's no point in iterating through the remaining
3366 elements of the array. */
3367 if (max_offset && INT_CST_LT (max_offset, offset))
3375 /* Record all of the empty subobjects of TYPE (either a type or a
3376 binfo). If IS_DATA_MEMBER is true, then a non-static data member
3377 is being placed at OFFSET; otherwise, it is a base class that is
3378 being placed at OFFSET. */
3381 record_subobject_offsets (tree type,
3384 bool is_data_member)
3387 /* If recording subobjects for a non-static data member or a
3388 non-empty base class , we do not need to record offsets beyond
3389 the size of the biggest empty class. Additional data members
3390 will go at the end of the class. Additional base classes will go
3391 either at offset zero (if empty, in which case they cannot
3392 overlap with offsets past the size of the biggest empty class) or
3393 at the end of the class.
3395 However, if we are placing an empty base class, then we must record
3396 all offsets, as either the empty class is at offset zero (where
3397 other empty classes might later be placed) or at the end of the
3398 class (where other objects might then be placed, so other empty
3399 subobjects might later overlap). */
3401 || !is_empty_class (BINFO_TYPE (type)))
3402 max_offset = sizeof_biggest_empty_class;
3404 max_offset = NULL_TREE;
3405 walk_subobject_offsets (type, record_subobject_offset, offset,
3406 offsets, max_offset, is_data_member);
3409 /* Returns nonzero if any of the empty subobjects of TYPE (located at
3410 OFFSET) conflict with entries in OFFSETS. If VBASES_P is nonzero,
3411 virtual bases of TYPE are examined. */
3414 layout_conflict_p (tree type,
3419 splay_tree_node max_node;
3421 /* Get the node in OFFSETS that indicates the maximum offset where
3422 an empty subobject is located. */
3423 max_node = splay_tree_max (offsets);
3424 /* If there aren't any empty subobjects, then there's no point in
3425 performing this check. */
3429 return walk_subobject_offsets (type, check_subobject_offset, offset,
3430 offsets, (tree) (max_node->key),
3434 /* DECL is a FIELD_DECL corresponding either to a base subobject of a
3435 non-static data member of the type indicated by RLI. BINFO is the
3436 binfo corresponding to the base subobject, OFFSETS maps offsets to
3437 types already located at those offsets. This function determines
3438 the position of the DECL. */
3441 layout_nonempty_base_or_field (record_layout_info rli,
3446 tree offset = NULL_TREE;
3452 /* For the purposes of determining layout conflicts, we want to
3453 use the class type of BINFO; TREE_TYPE (DECL) will be the
3454 CLASSTYPE_AS_BASE version, which does not contain entries for
3455 zero-sized bases. */
3456 type = TREE_TYPE (binfo);
3461 type = TREE_TYPE (decl);
3465 /* Try to place the field. It may take more than one try if we have
3466 a hard time placing the field without putting two objects of the
3467 same type at the same address. */
3470 struct record_layout_info_s old_rli = *rli;
3472 /* Place this field. */
3473 place_field (rli, decl);
3474 offset = byte_position (decl);
3476 /* We have to check to see whether or not there is already
3477 something of the same type at the offset we're about to use.
3478 For example, consider:
3481 struct T : public S { int i; };
3482 struct U : public S, public T {};
3484 Here, we put S at offset zero in U. Then, we can't put T at
3485 offset zero -- its S component would be at the same address
3486 as the S we already allocated. So, we have to skip ahead.
3487 Since all data members, including those whose type is an
3488 empty class, have nonzero size, any overlap can happen only
3489 with a direct or indirect base-class -- it can't happen with
3491 /* In a union, overlap is permitted; all members are placed at
3493 if (TREE_CODE (rli->t) == UNION_TYPE)
3495 /* G++ 3.2 did not check for overlaps when placing a non-empty
3497 if (!abi_version_at_least (2) && binfo && BINFO_VIRTUAL_P (binfo))
3499 if (layout_conflict_p (field_p ? type : binfo, offset,
3502 /* Strip off the size allocated to this field. That puts us
3503 at the first place we could have put the field with
3504 proper alignment. */
3507 /* Bump up by the alignment required for the type. */
3509 = size_binop (PLUS_EXPR, rli->bitpos,
3511 ? CLASSTYPE_ALIGN (type)
3512 : TYPE_ALIGN (type)));
3513 normalize_rli (rli);
3516 /* There was no conflict. We're done laying out this field. */
3520 /* Now that we know where it will be placed, update its
3522 if (binfo && CLASS_TYPE_P (BINFO_TYPE (binfo)))
3523 /* Indirect virtual bases may have a nonzero BINFO_OFFSET at
3524 this point because their BINFO_OFFSET is copied from another
3525 hierarchy. Therefore, we may not need to add the entire
3527 propagate_binfo_offsets (binfo,
3528 size_diffop (convert (ssizetype, offset),
3530 BINFO_OFFSET (binfo))));
3533 /* Returns true if TYPE is empty and OFFSET is nonzero. */
3536 empty_base_at_nonzero_offset_p (tree type,
3538 splay_tree offsets ATTRIBUTE_UNUSED)
3540 return is_empty_class (type) && !integer_zerop (offset);
3543 /* Layout the empty base BINFO. EOC indicates the byte currently just
3544 past the end of the class, and should be correctly aligned for a
3545 class of the type indicated by BINFO; OFFSETS gives the offsets of
3546 the empty bases allocated so far. T is the most derived
3547 type. Return nonzero iff we added it at the end. */
3550 layout_empty_base (record_layout_info rli, tree binfo,
3551 tree eoc, splay_tree offsets)
3554 tree basetype = BINFO_TYPE (binfo);
3557 /* This routine should only be used for empty classes. */
3558 gcc_assert (is_empty_class (basetype));
3559 alignment = ssize_int (CLASSTYPE_ALIGN_UNIT (basetype));
3561 if (!integer_zerop (BINFO_OFFSET (binfo)))
3563 if (abi_version_at_least (2))
3564 propagate_binfo_offsets
3565 (binfo, size_diffop (size_zero_node, BINFO_OFFSET (binfo)));
3568 "offset of empty base %qT may not be ABI-compliant and may"
3569 "change in a future version of GCC",
3570 BINFO_TYPE (binfo));
3573 /* This is an empty base class. We first try to put it at offset
3575 if (layout_conflict_p (binfo,
3576 BINFO_OFFSET (binfo),
3580 /* That didn't work. Now, we move forward from the next
3581 available spot in the class. */
3583 propagate_binfo_offsets (binfo, convert (ssizetype, eoc));
3586 if (!layout_conflict_p (binfo,
3587 BINFO_OFFSET (binfo),
3590 /* We finally found a spot where there's no overlap. */
3593 /* There's overlap here, too. Bump along to the next spot. */
3594 propagate_binfo_offsets (binfo, alignment);
3598 if (CLASSTYPE_USER_ALIGN (basetype))
3600 rli->record_align = MAX (rli->record_align, CLASSTYPE_ALIGN (basetype));
3602 rli->unpacked_align = MAX (rli->unpacked_align, CLASSTYPE_ALIGN (basetype));
3603 TYPE_USER_ALIGN (rli->t) = 1;
3609 /* Layout the base given by BINFO in the class indicated by RLI.
3610 *BASE_ALIGN is a running maximum of the alignments of
3611 any base class. OFFSETS gives the location of empty base
3612 subobjects. T is the most derived type. Return nonzero if the new
3613 object cannot be nearly-empty. A new FIELD_DECL is inserted at
3614 *NEXT_FIELD, unless BINFO is for an empty base class.
3616 Returns the location at which the next field should be inserted. */
3619 build_base_field (record_layout_info rli, tree binfo,
3620 splay_tree offsets, tree *next_field)
3623 tree basetype = BINFO_TYPE (binfo);
3625 if (!COMPLETE_TYPE_P (basetype))
3626 /* This error is now reported in xref_tag, thus giving better
3627 location information. */
3630 /* Place the base class. */
3631 if (!is_empty_class (basetype))
3635 /* The containing class is non-empty because it has a non-empty
3637 CLASSTYPE_EMPTY_P (t) = 0;
3639 /* Create the FIELD_DECL. */
3640 decl = build_decl (FIELD_DECL, NULL_TREE, CLASSTYPE_AS_BASE (basetype));
3641 DECL_ARTIFICIAL (decl) = 1;
3642 DECL_IGNORED_P (decl) = 1;
3643 DECL_FIELD_CONTEXT (decl) = t;
3644 if (CLASSTYPE_AS_BASE (basetype))
3646 DECL_SIZE (decl) = CLASSTYPE_SIZE (basetype);
3647 DECL_SIZE_UNIT (decl) = CLASSTYPE_SIZE_UNIT (basetype);
3648 DECL_ALIGN (decl) = CLASSTYPE_ALIGN (basetype);
3649 DECL_USER_ALIGN (decl) = CLASSTYPE_USER_ALIGN (basetype);
3650 DECL_MODE (decl) = TYPE_MODE (basetype);
3651 DECL_FIELD_IS_BASE (decl) = 1;
3653 /* Try to place the field. It may take more than one try if we
3654 have a hard time placing the field without putting two
3655 objects of the same type at the same address. */
3656 layout_nonempty_base_or_field (rli, decl, binfo, offsets);
3657 /* Add the new FIELD_DECL to the list of fields for T. */
3658 TREE_CHAIN (decl) = *next_field;
3660 next_field = &TREE_CHAIN (decl);
3668 /* On some platforms (ARM), even empty classes will not be
3670 eoc = round_up (rli_size_unit_so_far (rli),
3671 CLASSTYPE_ALIGN_UNIT (basetype));
3672 atend = layout_empty_base (rli, binfo, eoc, offsets);
3673 /* A nearly-empty class "has no proper base class that is empty,
3674 not morally virtual, and at an offset other than zero." */
3675 if (!BINFO_VIRTUAL_P (binfo) && CLASSTYPE_NEARLY_EMPTY_P (t))
3678 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3679 /* The check above (used in G++ 3.2) is insufficient because
3680 an empty class placed at offset zero might itself have an
3681 empty base at a nonzero offset. */
3682 else if (walk_subobject_offsets (basetype,
3683 empty_base_at_nonzero_offset_p,
3686 /*max_offset=*/NULL_TREE,
3689 if (abi_version_at_least (2))
3690 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
3693 "class %qT will be considered nearly empty in a "
3694 "future version of GCC", t);
3698 /* We do not create a FIELD_DECL for empty base classes because
3699 it might overlap some other field. We want to be able to
3700 create CONSTRUCTORs for the class by iterating over the
3701 FIELD_DECLs, and the back end does not handle overlapping
3704 /* An empty virtual base causes a class to be non-empty
3705 -- but in that case we do not need to clear CLASSTYPE_EMPTY_P
3706 here because that was already done when the virtual table
3707 pointer was created. */
3710 /* Record the offsets of BINFO and its base subobjects. */
3711 record_subobject_offsets (binfo,
3712 BINFO_OFFSET (binfo),
3714 /*is_data_member=*/false);
3719 /* Layout all of the non-virtual base classes. Record empty
3720 subobjects in OFFSETS. T is the most derived type. Return nonzero
3721 if the type cannot be nearly empty. The fields created
3722 corresponding to the base classes will be inserted at
3726 build_base_fields (record_layout_info rli,
3727 splay_tree offsets, tree *next_field)
3729 /* Chain to hold all the new FIELD_DECLs which stand in for base class
3732 int n_baseclasses = BINFO_N_BASE_BINFOS (TYPE_BINFO (t));
3735 /* The primary base class is always allocated first. */
3736 if (CLASSTYPE_HAS_PRIMARY_BASE_P (t))
3737 next_field = build_base_field (rli, CLASSTYPE_PRIMARY_BINFO (t),
3738 offsets, next_field);
3740 /* Now allocate the rest of the bases. */
3741 for (i = 0; i < n_baseclasses; ++i)
3745 base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (t), i);
3747 /* The primary base was already allocated above, so we don't
3748 need to allocate it again here. */
3749 if (base_binfo == CLASSTYPE_PRIMARY_BINFO (t))
3752 /* Virtual bases are added at the end (a primary virtual base
3753 will have already been added). */
3754 if (BINFO_VIRTUAL_P (base_binfo))
3757 next_field = build_base_field (rli, base_binfo,
3758 offsets, next_field);
3762 /* Go through the TYPE_METHODS of T issuing any appropriate
3763 diagnostics, figuring out which methods override which other
3764 methods, and so forth. */
3767 check_methods (tree t)
3771 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
3773 check_for_override (x, t);
3774 if (DECL_PURE_VIRTUAL_P (x) && ! DECL_VINDEX (x))
3775 error ("initializer specified for non-virtual method %q+D", x);
3776 /* The name of the field is the original field name
3777 Save this in auxiliary field for later overloading. */
3778 if (DECL_VINDEX (x))
3780 TYPE_POLYMORPHIC_P (t) = 1;
3781 if (DECL_PURE_VIRTUAL_P (x))
3782 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
3784 /* All user-provided destructors are non-trivial. */
3785 if (DECL_DESTRUCTOR_P (x) && !DECL_DEFAULTED_FN (x))
3786 TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t) = 1;
3790 /* FN is a constructor or destructor. Clone the declaration to create
3791 a specialized in-charge or not-in-charge version, as indicated by
3795 build_clone (tree fn, tree name)
3800 /* Copy the function. */
3801 clone = copy_decl (fn);
3802 /* Remember where this function came from. */
3803 DECL_CLONED_FUNCTION (clone) = fn;
3804 DECL_ABSTRACT_ORIGIN (clone) = fn;
3805 /* Reset the function name. */
3806 DECL_NAME (clone) = name;
3807 SET_DECL_ASSEMBLER_NAME (clone, NULL_TREE);
3808 /* There's no pending inline data for this function. */
3809 DECL_PENDING_INLINE_INFO (clone) = NULL;
3810 DECL_PENDING_INLINE_P (clone) = 0;
3811 /* And it hasn't yet been deferred. */
3812 DECL_DEFERRED_FN (clone) = 0;
3814 /* The base-class destructor is not virtual. */
3815 if (name == base_dtor_identifier)
3817 DECL_VIRTUAL_P (clone) = 0;
3818 if (TREE_CODE (clone) != TEMPLATE_DECL)
3819 DECL_VINDEX (clone) = NULL_TREE;
3822 /* If there was an in-charge parameter, drop it from the function
3824 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3830 exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
3831 basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
3832 parmtypes = TYPE_ARG_TYPES (TREE_TYPE (clone));
3833 /* Skip the `this' parameter. */
3834 parmtypes = TREE_CHAIN (parmtypes);
3835 /* Skip the in-charge parameter. */
3836 parmtypes = TREE_CHAIN (parmtypes);
3837 /* And the VTT parm, in a complete [cd]tor. */
3838 if (DECL_HAS_VTT_PARM_P (fn)
3839 && ! DECL_NEEDS_VTT_PARM_P (clone))
3840 parmtypes = TREE_CHAIN (parmtypes);
3841 /* If this is subobject constructor or destructor, add the vtt
3844 = build_method_type_directly (basetype,
3845 TREE_TYPE (TREE_TYPE (clone)),
3848 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone),
3851 = cp_build_type_attribute_variant (TREE_TYPE (clone),
3852 TYPE_ATTRIBUTES (TREE_TYPE (fn)));
3855 /* Copy the function parameters. But, DECL_ARGUMENTS on a TEMPLATE_DECL
3856 aren't function parameters; those are the template parameters. */
3857 if (TREE_CODE (clone) != TEMPLATE_DECL)
3859 DECL_ARGUMENTS (clone) = copy_list (DECL_ARGUMENTS (clone));
3860 /* Remove the in-charge parameter. */
3861 if (DECL_HAS_IN_CHARGE_PARM_P (clone))
3863 TREE_CHAIN (DECL_ARGUMENTS (clone))
3864 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3865 DECL_HAS_IN_CHARGE_PARM_P (clone) = 0;
3867 /* And the VTT parm, in a complete [cd]tor. */
3868 if (DECL_HAS_VTT_PARM_P (fn))
3870 if (DECL_NEEDS_VTT_PARM_P (clone))
3871 DECL_HAS_VTT_PARM_P (clone) = 1;
3874 TREE_CHAIN (DECL_ARGUMENTS (clone))
3875 = TREE_CHAIN (TREE_CHAIN (DECL_ARGUMENTS (clone)));
3876 DECL_HAS_VTT_PARM_P (clone) = 0;
3880 for (parms = DECL_ARGUMENTS (clone); parms; parms = TREE_CHAIN (parms))
3882 DECL_CONTEXT (parms) = clone;
3883 cxx_dup_lang_specific_decl (parms);
3887 /* Create the RTL for this function. */
3888 SET_DECL_RTL (clone, NULL_RTX);
3889 rest_of_decl_compilation (clone, /*top_level=*/1, at_eof);
3891 /* Make it easy to find the CLONE given the FN. */
3892 TREE_CHAIN (clone) = TREE_CHAIN (fn);
3893 TREE_CHAIN (fn) = clone;
3895 /* If this is a template, handle the DECL_TEMPLATE_RESULT as well. */
3896 if (TREE_CODE (clone) == TEMPLATE_DECL)
3900 DECL_TEMPLATE_RESULT (clone)
3901 = build_clone (DECL_TEMPLATE_RESULT (clone), name);
3902 result = DECL_TEMPLATE_RESULT (clone);
3903 DECL_TEMPLATE_INFO (result) = copy_node (DECL_TEMPLATE_INFO (result));
3904 DECL_TI_TEMPLATE (result) = clone;
3907 note_decl_for_pch (clone);
3912 /* Produce declarations for all appropriate clones of FN. If
3913 UPDATE_METHOD_VEC_P is nonzero, the clones are added to the
3914 CLASTYPE_METHOD_VEC as well. */
3917 clone_function_decl (tree fn, int update_method_vec_p)
3921 /* Avoid inappropriate cloning. */
3923 && DECL_CLONED_FUNCTION (TREE_CHAIN (fn)))
3926 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
3928 /* For each constructor, we need two variants: an in-charge version
3929 and a not-in-charge version. */
3930 clone = build_clone (fn, complete_ctor_identifier);
3931 if (update_method_vec_p)
3932 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3933 clone = build_clone (fn, base_ctor_identifier);
3934 if (update_method_vec_p)
3935 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3939 gcc_assert (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn));
3941 /* For each destructor, we need three variants: an in-charge
3942 version, a not-in-charge version, and an in-charge deleting
3943 version. We clone the deleting version first because that
3944 means it will go second on the TYPE_METHODS list -- and that
3945 corresponds to the correct layout order in the virtual
3948 For a non-virtual destructor, we do not build a deleting
3950 if (DECL_VIRTUAL_P (fn))
3952 clone = build_clone (fn, deleting_dtor_identifier);
3953 if (update_method_vec_p)
3954 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3956 clone = build_clone (fn, complete_dtor_identifier);
3957 if (update_method_vec_p)
3958 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3959 clone = build_clone (fn, base_dtor_identifier);
3960 if (update_method_vec_p)
3961 add_method (DECL_CONTEXT (clone), clone, NULL_TREE);
3964 /* Note that this is an abstract function that is never emitted. */
3965 DECL_ABSTRACT (fn) = 1;
3968 /* DECL is an in charge constructor, which is being defined. This will
3969 have had an in class declaration, from whence clones were
3970 declared. An out-of-class definition can specify additional default
3971 arguments. As it is the clones that are involved in overload
3972 resolution, we must propagate the information from the DECL to its
3976 adjust_clone_args (tree decl)
3980 for (clone = TREE_CHAIN (decl); clone && DECL_CLONED_FUNCTION (clone);
3981 clone = TREE_CHAIN (clone))
3983 tree orig_clone_parms = TYPE_ARG_TYPES (TREE_TYPE (clone));
3984 tree orig_decl_parms = TYPE_ARG_TYPES (TREE_TYPE (decl));
3985 tree decl_parms, clone_parms;
3987 clone_parms = orig_clone_parms;
3989 /* Skip the 'this' parameter. */
3990 orig_clone_parms = TREE_CHAIN (orig_clone_parms);
3991 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3993 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
3994 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3995 if (DECL_HAS_VTT_PARM_P (decl))
3996 orig_decl_parms = TREE_CHAIN (orig_decl_parms);
3998 clone_parms = orig_clone_parms;
3999 if (DECL_HAS_VTT_PARM_P (clone))
4000 clone_parms = TREE_CHAIN (clone_parms);
4002 for (decl_parms = orig_decl_parms; decl_parms;
4003 decl_parms = TREE_CHAIN (decl_parms),
4004 clone_parms = TREE_CHAIN (clone_parms))
4006 gcc_assert (same_type_p (TREE_TYPE (decl_parms),
4007 TREE_TYPE (clone_parms)));
4009 if (TREE_PURPOSE (decl_parms) && !TREE_PURPOSE (clone_parms))
4011 /* A default parameter has been added. Adjust the
4012 clone's parameters. */
4013 tree exceptions = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (clone));
4014 tree basetype = TYPE_METHOD_BASETYPE (TREE_TYPE (clone));
4017 clone_parms = orig_decl_parms;
4019 if (DECL_HAS_VTT_PARM_P (clone))
4021 clone_parms = tree_cons (TREE_PURPOSE (orig_clone_parms),
4022 TREE_VALUE (orig_clone_parms),
4024 TREE_TYPE (clone_parms) = TREE_TYPE (orig_clone_parms);
4026 type = build_method_type_directly (basetype,
4027 TREE_TYPE (TREE_TYPE (clone)),
4030 type = build_exception_variant (type, exceptions);
4031 TREE_TYPE (clone) = type;
4033 clone_parms = NULL_TREE;
4037 gcc_assert (!clone_parms);
4041 /* For each of the constructors and destructors in T, create an
4042 in-charge and not-in-charge variant. */
4045 clone_constructors_and_destructors (tree t)
4049 /* If for some reason we don't have a CLASSTYPE_METHOD_VEC, we bail
4051 if (!CLASSTYPE_METHOD_VEC (t))
4054 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4055 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4056 for (fns = CLASSTYPE_DESTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4057 clone_function_decl (OVL_CURRENT (fns), /*update_method_vec_p=*/1);
4060 /* Returns true iff class T has a user-defined constructor other than
4061 the default constructor. */
4064 type_has_user_nondefault_constructor (tree t)
4068 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4071 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4073 tree fn = OVL_CURRENT (fns);
4074 if (!DECL_ARTIFICIAL (fn)
4075 && (TREE_CODE (fn) == TEMPLATE_DECL
4076 || (skip_artificial_parms_for (fn, DECL_ARGUMENTS (fn))
4084 /* Returns true iff FN is a user-provided function, i.e. user-declared
4085 and not defaulted at its first declaration. */
4088 user_provided_p (tree fn)
4090 if (TREE_CODE (fn) == TEMPLATE_DECL)
4093 return (!DECL_ARTIFICIAL (fn)
4094 && !(DECL_DEFAULTED_FN (fn)
4095 && DECL_INITIALIZED_IN_CLASS_P (fn)));
4098 /* Returns true iff class T has a user-provided constructor. */
4101 type_has_user_provided_constructor (tree t)
4105 if (!CLASS_TYPE_P (t))
4108 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4111 /* This can happen in error cases; avoid crashing. */
4112 if (!CLASSTYPE_METHOD_VEC (t))
4115 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4116 if (user_provided_p (OVL_CURRENT (fns)))
4122 /* Returns true iff class T has a user-provided default constructor. */
4125 type_has_user_provided_default_constructor (tree t)
4129 if (!TYPE_HAS_USER_CONSTRUCTOR (t))
4132 for (fns = CLASSTYPE_CONSTRUCTORS (t); fns; fns = OVL_NEXT (fns))
4134 tree fn = OVL_CURRENT (fns);
4135 if (TREE_CODE (fn) == FUNCTION_DECL
4136 && user_provided_p (fn))
4138 args = FUNCTION_FIRST_USER_PARMTYPE (fn);
4139 while (args && TREE_PURPOSE (args))
4140 args = TREE_CHAIN (args);
4141 if (!args || args == void_list_node)
4149 /* Returns true if FN can be explicitly defaulted. */
4152 defaultable_fn_p (tree fn)
4154 if (DECL_CONSTRUCTOR_P (fn))
4156 if (FUNCTION_FIRST_USER_PARMTYPE (fn) == void_list_node)
4158 else if (copy_fn_p (fn) > 0
4159 && (TREE_CHAIN (FUNCTION_FIRST_USER_PARMTYPE (fn))
4165 else if (DECL_DESTRUCTOR_P (fn))
4167 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
4168 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
4169 return copy_fn_p (fn);
4174 /* Remove all zero-width bit-fields from T. */
4177 remove_zero_width_bit_fields (tree t)
4181 fieldsp = &TYPE_FIELDS (t);
4184 if (TREE_CODE (*fieldsp) == FIELD_DECL
4185 && DECL_C_BIT_FIELD (*fieldsp)
4186 && DECL_INITIAL (*fieldsp))
4187 *fieldsp = TREE_CHAIN (*fieldsp);
4189 fieldsp = &TREE_CHAIN (*fieldsp);
4193 /* Returns TRUE iff we need a cookie when dynamically allocating an
4194 array whose elements have the indicated class TYPE. */
4197 type_requires_array_cookie (tree type)
4200 bool has_two_argument_delete_p = false;
4202 gcc_assert (CLASS_TYPE_P (type));
4204 /* If there's a non-trivial destructor, we need a cookie. In order
4205 to iterate through the array calling the destructor for each
4206 element, we'll have to know how many elements there are. */
4207 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
4210 /* If the usual deallocation function is a two-argument whose second
4211 argument is of type `size_t', then we have to pass the size of
4212 the array to the deallocation function, so we will need to store
4214 fns = lookup_fnfields (TYPE_BINFO (type),
4215 ansi_opname (VEC_DELETE_EXPR),
4217 /* If there are no `operator []' members, or the lookup is
4218 ambiguous, then we don't need a cookie. */
4219 if (!fns || fns == error_mark_node)
4221 /* Loop through all of the functions. */
4222 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
4227 /* Select the current function. */
4228 fn = OVL_CURRENT (fns);
4229 /* See if this function is a one-argument delete function. If
4230 it is, then it will be the usual deallocation function. */
4231 second_parm = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fn)));
4232 if (second_parm == void_list_node)
4234 /* Do not consider this function if its second argument is an
4238 /* Otherwise, if we have a two-argument function and the second
4239 argument is `size_t', it will be the usual deallocation
4240 function -- unless there is one-argument function, too. */
4241 if (TREE_CHAIN (second_parm) == void_list_node
4242 && same_type_p (TREE_VALUE (second_parm), size_type_node))
4243 has_two_argument_delete_p = true;
4246 return has_two_argument_delete_p;
4249 /* Check the validity of the bases and members declared in T. Add any
4250 implicitly-generated functions (like copy-constructors and
4251 assignment operators). Compute various flag bits (like
4252 CLASSTYPE_NON_POD_T) for T. This routine works purely at the C++
4253 level: i.e., independently of the ABI in use. */
4256 check_bases_and_members (tree t)
4258 /* Nonzero if the implicitly generated copy constructor should take
4259 a non-const reference argument. */
4260 int cant_have_const_ctor;
4261 /* Nonzero if the implicitly generated assignment operator
4262 should take a non-const reference argument. */
4263 int no_const_asn_ref;
4265 bool saved_complex_asn_ref;
4266 bool saved_nontrivial_dtor;
4268 /* By default, we use const reference arguments and generate default
4270 cant_have_const_ctor = 0;
4271 no_const_asn_ref = 0;
4273 /* Check all the base-classes. */
4274 check_bases (t, &cant_have_const_ctor,
4277 /* Check all the method declarations. */
4280 /* Save the initial values of these flags which only indicate whether
4281 or not the class has user-provided functions. As we analyze the
4282 bases and members we can set these flags for other reasons. */
4283 saved_complex_asn_ref = TYPE_HAS_COMPLEX_ASSIGN_REF (t);
4284 saved_nontrivial_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (t);
4286 /* Check all the data member declarations. We cannot call
4287 check_field_decls until we have called check_bases check_methods,
4288 as check_field_decls depends on TYPE_HAS_NONTRIVIAL_DESTRUCTOR
4289 being set appropriately. */
4290 check_field_decls (t, &access_decls,
4291 &cant_have_const_ctor,
4294 /* A nearly-empty class has to be vptr-containing; a nearly empty
4295 class contains just a vptr. */
4296 if (!TYPE_CONTAINS_VPTR_P (t))
4297 CLASSTYPE_NEARLY_EMPTY_P (t) = 0;
4299 /* Do some bookkeeping that will guide the generation of implicitly
4300 declared member functions. */
4301 TYPE_HAS_COMPLEX_INIT_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4302 /* We need to call a constructor for this class if it has a
4303 user-provided constructor, or if the default constructor is going
4304 to initialize the vptr. (This is not an if-and-only-if;
4305 TYPE_NEEDS_CONSTRUCTING is set elsewhere if bases or members
4306 themselves need constructing.) */
4307 TYPE_NEEDS_CONSTRUCTING (t)
4308 |= (type_has_user_provided_constructor (t) || TYPE_CONTAINS_VPTR_P (t));
4311 An aggregate is an array or a class with no user-provided
4312 constructors ... and no virtual functions.
4314 Again, other conditions for being an aggregate are checked
4316 CLASSTYPE_NON_AGGREGATE (t)
4317 |= (type_has_user_provided_constructor (t) || TYPE_POLYMORPHIC_P (t));
4318 CLASSTYPE_NON_POD_P (t)
4319 |= (CLASSTYPE_NON_AGGREGATE (t)
4320 || saved_nontrivial_dtor || saved_complex_asn_ref);
4321 TYPE_HAS_COMPLEX_ASSIGN_REF (t) |= TYPE_CONTAINS_VPTR_P (t);
4322 TYPE_HAS_COMPLEX_DFLT (t) |= TYPE_CONTAINS_VPTR_P (t);
4324 /* If the class has no user-declared constructor, but does have
4325 non-static const or reference data members that can never be
4326 initialized, issue a warning. */
4327 if (warn_uninitialized
4328 /* Classes with user-declared constructors are presumed to
4329 initialize these members. */
4330 && !TYPE_HAS_USER_CONSTRUCTOR (t)
4331 /* Aggregates can be initialized with brace-enclosed
4333 && CLASSTYPE_NON_AGGREGATE (t))
4337 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
4341 if (TREE_CODE (field) != FIELD_DECL)
4344 type = TREE_TYPE (field);
4345 if (TREE_CODE (type) == REFERENCE_TYPE)
4346 warning (OPT_Wuninitialized, "non-static reference %q+#D "
4347 "in class without a constructor", field);
4348 else if (CP_TYPE_CONST_P (type)
4349 && (!CLASS_TYPE_P (type)
4350 || !TYPE_HAS_DEFAULT_CONSTRUCTOR (type)))
4351 warning (OPT_Wuninitialized, "non-static const member %q+#D "
4352 "in class without a constructor", field);
4356 /* Synthesize any needed methods. */
4357 add_implicitly_declared_members (t,
4358 cant_have_const_ctor,
4361 /* Create the in-charge and not-in-charge variants of constructors
4363 clone_constructors_and_destructors (t);
4365 /* Process the using-declarations. */
4366 for (; access_decls; access_decls = TREE_CHAIN (access_decls))
4367 handle_using_decl (TREE_VALUE (access_decls), t);
4369 /* Build and sort the CLASSTYPE_METHOD_VEC. */
4370 finish_struct_methods (t);
4372 /* Figure out whether or not we will need a cookie when dynamically
4373 allocating an array of this type. */
4374 TYPE_LANG_SPECIFIC (t)->u.c.vec_new_uses_cookie
4375 = type_requires_array_cookie (t);
4378 /* If T needs a pointer to its virtual function table, set TYPE_VFIELD
4379 accordingly. If a new vfield was created (because T doesn't have a
4380 primary base class), then the newly created field is returned. It
4381 is not added to the TYPE_FIELDS list; it is the caller's
4382 responsibility to do that. Accumulate declared virtual functions
4386 create_vtable_ptr (tree t, tree* virtuals_p)
4390 /* Collect the virtual functions declared in T. */
4391 for (fn = TYPE_METHODS (t); fn; fn = TREE_CHAIN (fn))
4392 if (DECL_VINDEX (fn) && !DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fn)
4393 && TREE_CODE (DECL_VINDEX (fn)) != INTEGER_CST)
4395 tree new_virtual = make_node (TREE_LIST);
4397 BV_FN (new_virtual) = fn;
4398 BV_DELTA (new_virtual) = integer_zero_node;
4399 BV_VCALL_INDEX (new_virtual) = NULL_TREE;
4401 TREE_CHAIN (new_virtual) = *virtuals_p;
4402 *virtuals_p = new_virtual;
4405 /* If we couldn't find an appropriate base class, create a new field
4406 here. Even if there weren't any new virtual functions, we might need a
4407 new virtual function table if we're supposed to include vptrs in
4408 all classes that need them. */
4409 if (!TYPE_VFIELD (t) && (*virtuals_p || TYPE_CONTAINS_VPTR_P (t)))
4411 /* We build this decl with vtbl_ptr_type_node, which is a
4412 `vtable_entry_type*'. It might seem more precise to use
4413 `vtable_entry_type (*)[N]' where N is the number of virtual
4414 functions. However, that would require the vtable pointer in
4415 base classes to have a different type than the vtable pointer
4416 in derived classes. We could make that happen, but that
4417 still wouldn't solve all the problems. In particular, the
4418 type-based alias analysis code would decide that assignments
4419 to the base class vtable pointer can't alias assignments to
4420 the derived class vtable pointer, since they have different
4421 types. Thus, in a derived class destructor, where the base
4422 class constructor was inlined, we could generate bad code for
4423 setting up the vtable pointer.
4425 Therefore, we use one type for all vtable pointers. We still
4426 use a type-correct type; it's just doesn't indicate the array
4427 bounds. That's better than using `void*' or some such; it's
4428 cleaner, and it let's the alias analysis code know that these
4429 stores cannot alias stores to void*! */
4432 field = build_decl (FIELD_DECL, get_vfield_name (t), vtbl_ptr_type_node);
4433 DECL_VIRTUAL_P (field) = 1;
4434 DECL_ARTIFICIAL (field) = 1;
4435 DECL_FIELD_CONTEXT (field) = t;
4436 DECL_FCONTEXT (field) = t;
4438 TYPE_VFIELD (t) = field;
4440 /* This class is non-empty. */
4441 CLASSTYPE_EMPTY_P (t) = 0;
4449 /* Fixup the inline function given by INFO now that the class is
4453 fixup_pending_inline (tree fn)
4455 if (DECL_PENDING_INLINE_INFO (fn))
4457 tree args = DECL_ARGUMENTS (fn);
4460 DECL_CONTEXT (args) = fn;
4461 args = TREE_CHAIN (args);
4466 /* Fixup the inline methods and friends in TYPE now that TYPE is
4470 fixup_inline_methods (tree type)
4472 tree method = TYPE_METHODS (type);
4473 VEC(tree,gc) *friends;
4476 if (method && TREE_CODE (method) == TREE_VEC)
4478 if (TREE_VEC_ELT (method, 1))
4479 method = TREE_VEC_ELT (method, 1);
4480 else if (TREE_VEC_ELT (method, 0))
4481 method = TREE_VEC_ELT (method, 0);
4483 method = TREE_VEC_ELT (method, 2);
4486 /* Do inline member functions. */
4487 for (; method; method = TREE_CHAIN (method))
4488 fixup_pending_inline (method);
4491 for (friends = CLASSTYPE_INLINE_FRIENDS (type), ix = 0;
4492 VEC_iterate (tree, friends, ix, method); ix++)
4493 fixup_pending_inline (method);
4494 CLASSTYPE_INLINE_FRIENDS (type) = NULL;
4497 /* Add OFFSET to all base types of BINFO which is a base in the
4498 hierarchy dominated by T.
4500 OFFSET, which is a type offset, is number of bytes. */
4503 propagate_binfo_offsets (tree binfo, tree offset)
4509 /* Update BINFO's offset. */
4510 BINFO_OFFSET (binfo)
4511 = convert (sizetype,
4512 size_binop (PLUS_EXPR,
4513 convert (ssizetype, BINFO_OFFSET (binfo)),
4516 /* Find the primary base class. */
4517 primary_binfo = get_primary_binfo (binfo);
4519 if (primary_binfo && BINFO_INHERITANCE_CHAIN (primary_binfo) == binfo)
4520 propagate_binfo_offsets (primary_binfo, offset);
4522 /* Scan all of the bases, pushing the BINFO_OFFSET adjust
4524 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4526 /* Don't do the primary base twice. */
4527 if (base_binfo == primary_binfo)
4530 if (BINFO_VIRTUAL_P (base_binfo))
4533 propagate_binfo_offsets (base_binfo, offset);
4537 /* Set BINFO_OFFSET for all of the virtual bases for RLI->T. Update
4538 TYPE_ALIGN and TYPE_SIZE for T. OFFSETS gives the location of
4539 empty subobjects of T. */
4542 layout_virtual_bases (record_layout_info rli, splay_tree offsets)
4546 bool first_vbase = true;
4549 if (BINFO_N_BASE_BINFOS (TYPE_BINFO (t)) == 0)
4552 if (!abi_version_at_least(2))
4554 /* In G++ 3.2, we incorrectly rounded the size before laying out
4555 the virtual bases. */
4556 finish_record_layout (rli, /*free_p=*/false);
4557 #ifdef STRUCTURE_SIZE_BOUNDARY
4558 /* Packed structures don't need to have minimum size. */
4559 if (! TYPE_PACKED (t))
4560 TYPE_ALIGN (t) = MAX (TYPE_ALIGN (t), (unsigned) STRUCTURE_SIZE_BOUNDARY);
4562 rli->offset = TYPE_SIZE_UNIT (t);
4563 rli->bitpos = bitsize_zero_node;
4564 rli->record_align = TYPE_ALIGN (t);
4567 /* Find the last field. The artificial fields created for virtual
4568 bases will go after the last extant field to date. */
4569 next_field = &TYPE_FIELDS (t);
4571 next_field = &TREE_CHAIN (*next_field);
4573 /* Go through the virtual bases, allocating space for each virtual
4574 base that is not already a primary base class. These are
4575 allocated in inheritance graph order. */
4576 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
4578 if (!BINFO_VIRTUAL_P (vbase))
4581 if (!BINFO_PRIMARY_P (vbase))
4583 tree basetype = TREE_TYPE (vbase);
4585 /* This virtual base is not a primary base of any class in the
4586 hierarchy, so we have to add space for it. */
4587 next_field = build_base_field (rli, vbase,
4588 offsets, next_field);
4590 /* If the first virtual base might have been placed at a
4591 lower address, had we started from CLASSTYPE_SIZE, rather
4592 than TYPE_SIZE, issue a warning. There can be both false
4593 positives and false negatives from this warning in rare
4594 cases; to deal with all the possibilities would probably
4595 require performing both layout algorithms and comparing
4596 the results which is not particularly tractable. */
4600 (size_binop (CEIL_DIV_EXPR,
4601 round_up (CLASSTYPE_SIZE (t),
4602 CLASSTYPE_ALIGN (basetype)),
4604 BINFO_OFFSET (vbase))))
4606 "offset of virtual base %qT is not ABI-compliant and "
4607 "may change in a future version of GCC",
4610 first_vbase = false;
4615 /* Returns the offset of the byte just past the end of the base class
4619 end_of_base (tree binfo)
4623 if (!CLASSTYPE_AS_BASE (BINFO_TYPE (binfo)))
4624 size = TYPE_SIZE_UNIT (char_type_node);
4625 else if (is_empty_class (BINFO_TYPE (binfo)))
4626 /* An empty class has zero CLASSTYPE_SIZE_UNIT, but we need to
4627 allocate some space for it. It cannot have virtual bases, so
4628 TYPE_SIZE_UNIT is fine. */
4629 size = TYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4631 size = CLASSTYPE_SIZE_UNIT (BINFO_TYPE (binfo));
4633 return size_binop (PLUS_EXPR, BINFO_OFFSET (binfo), size);
4636 /* Returns the offset of the byte just past the end of the base class
4637 with the highest offset in T. If INCLUDE_VIRTUALS_P is zero, then
4638 only non-virtual bases are included. */
4641 end_of_class (tree t, int include_virtuals_p)
4643 tree result = size_zero_node;
4644 VEC(tree,gc) *vbases;
4650 for (binfo = TYPE_BINFO (t), i = 0;
4651 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4653 if (!include_virtuals_p
4654 && BINFO_VIRTUAL_P (base_binfo)
4655 && (!BINFO_PRIMARY_P (base_binfo)
4656 || BINFO_INHERITANCE_CHAIN (base_binfo) != TYPE_BINFO (t)))
4659 offset = end_of_base (base_binfo);
4660 if (INT_CST_LT_UNSIGNED (result, offset))
4664 /* G++ 3.2 did not check indirect virtual bases. */
4665 if (abi_version_at_least (2) && include_virtuals_p)
4666 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4667 VEC_iterate (tree, vbases, i, base_binfo); i++)
4669 offset = end_of_base (base_binfo);
4670 if (INT_CST_LT_UNSIGNED (result, offset))
4677 /* Warn about bases of T that are inaccessible because they are
4678 ambiguous. For example:
4681 struct T : public S {};
4682 struct U : public S, public T {};
4684 Here, `(S*) new U' is not allowed because there are two `S'
4688 warn_about_ambiguous_bases (tree t)
4691 VEC(tree,gc) *vbases;
4696 /* If there are no repeated bases, nothing can be ambiguous. */
4697 if (!CLASSTYPE_REPEATED_BASE_P (t))
4700 /* Check direct bases. */
4701 for (binfo = TYPE_BINFO (t), i = 0;
4702 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
4704 basetype = BINFO_TYPE (base_binfo);
4706 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4707 warning (0, "direct base %qT inaccessible in %qT due to ambiguity",
4711 /* Check for ambiguous virtual bases. */
4713 for (vbases = CLASSTYPE_VBASECLASSES (t), i = 0;
4714 VEC_iterate (tree, vbases, i, binfo); i++)
4716 basetype = BINFO_TYPE (binfo);
4718 if (!lookup_base (t, basetype, ba_unique | ba_quiet, NULL))
4719 warning (OPT_Wextra, "virtual base %qT inaccessible in %qT due to ambiguity",
4724 /* Compare two INTEGER_CSTs K1 and K2. */
4727 splay_tree_compare_integer_csts (splay_tree_key k1, splay_tree_key k2)
4729 return tree_int_cst_compare ((tree) k1, (tree) k2);
4732 /* Increase the size indicated in RLI to account for empty classes
4733 that are "off the end" of the class. */
4736 include_empty_classes (record_layout_info rli)
4741 /* It might be the case that we grew the class to allocate a
4742 zero-sized base class. That won't be reflected in RLI, yet,
4743 because we are willing to overlay multiple bases at the same
4744 offset. However, now we need to make sure that RLI is big enough
4745 to reflect the entire class. */
4746 eoc = end_of_class (rli->t,
4747 CLASSTYPE_AS_BASE (rli->t) != NULL_TREE);
4748 rli_size = rli_size_unit_so_far (rli);
4749 if (TREE_CODE (rli_size) == INTEGER_CST
4750 && INT_CST_LT_UNSIGNED (rli_size, eoc))
4752 if (!abi_version_at_least (2))
4753 /* In version 1 of the ABI, the size of a class that ends with
4754 a bitfield was not rounded up to a whole multiple of a
4755 byte. Because rli_size_unit_so_far returns only the number
4756 of fully allocated bytes, any extra bits were not included
4758 rli->bitpos = round_down (rli->bitpos, BITS_PER_UNIT);
4760 /* The size should have been rounded to a whole byte. */
4761 gcc_assert (tree_int_cst_equal
4762 (rli->bitpos, round_down (rli->bitpos, BITS_PER_UNIT)));
4764 = size_binop (PLUS_EXPR,
4766 size_binop (MULT_EXPR,
4767 convert (bitsizetype,
4768 size_binop (MINUS_EXPR,
4770 bitsize_int (BITS_PER_UNIT)));
4771 normalize_rli (rli);
4775 /* Calculate the TYPE_SIZE, TYPE_ALIGN, etc for T. Calculate
4776 BINFO_OFFSETs for all of the base-classes. Position the vtable
4777 pointer. Accumulate declared virtual functions on VIRTUALS_P. */
4780 layout_class_type (tree t, tree *virtuals_p)
4782 tree non_static_data_members;
4785 record_layout_info rli;
4786 /* Maps offsets (represented as INTEGER_CSTs) to a TREE_LIST of
4787 types that appear at that offset. */
4788 splay_tree empty_base_offsets;
4789 /* True if the last field layed out was a bit-field. */
4790 bool last_field_was_bitfield = false;
4791 /* The location at which the next field should be inserted. */
4793 /* T, as a base class. */
4796 /* Keep track of the first non-static data member. */
4797 non_static_data_members = TYPE_FIELDS (t);
4799 /* Start laying out the record. */
4800 rli = start_record_layout (t);
4802 /* Mark all the primary bases in the hierarchy. */
4803 determine_primary_bases (t);
4805 /* Create a pointer to our virtual function table. */
4806 vptr = create_vtable_ptr (t, virtuals_p);
4808 /* The vptr is always the first thing in the class. */
4811 TREE_CHAIN (vptr) = TYPE_FIELDS (t);
4812 TYPE_FIELDS (t) = vptr;
4813 next_field = &TREE_CHAIN (vptr);
4814 place_field (rli, vptr);
4817 next_field = &TYPE_FIELDS (t);
4819 /* Build FIELD_DECLs for all of the non-virtual base-types. */
4820 empty_base_offsets = splay_tree_new (splay_tree_compare_integer_csts,
4822 build_base_fields (rli, empty_base_offsets, next_field);
4824 /* Layout the non-static data members. */
4825 for (field = non_static_data_members; field; field = TREE_CHAIN (field))
4830 /* We still pass things that aren't non-static data members to
4831 the back end, in case it wants to do something with them. */
4832 if (TREE_CODE (field) != FIELD_DECL)
4834 place_field (rli, field);
4835 /* If the static data member has incomplete type, keep track
4836 of it so that it can be completed later. (The handling
4837 of pending statics in finish_record_layout is
4838 insufficient; consider:
4841 struct S2 { static S1 s1; };
4843 At this point, finish_record_layout will be called, but
4844 S1 is still incomplete.) */
4845 if (TREE_CODE (field) == VAR_DECL)
4847 maybe_register_incomplete_var (field);
4848 /* The visibility of static data members is determined
4849 at their point of declaration, not their point of
4851 determine_visibility (field);
4856 type = TREE_TYPE (field);
4857 if (type == error_mark_node)
4860 padding = NULL_TREE;
4862 /* If this field is a bit-field whose width is greater than its
4863 type, then there are some special rules for allocating
4865 if (DECL_C_BIT_FIELD (field)
4866 && INT_CST_LT (TYPE_SIZE (type), DECL_SIZE (field)))
4868 integer_type_kind itk;
4870 bool was_unnamed_p = false;
4871 /* We must allocate the bits as if suitably aligned for the
4872 longest integer type that fits in this many bits. type
4873 of the field. Then, we are supposed to use the left over
4874 bits as additional padding. */
4875 for (itk = itk_char; itk != itk_none; ++itk)
4876 if (INT_CST_LT (DECL_SIZE (field),
4877 TYPE_SIZE (integer_types[itk])))
4880 /* ITK now indicates a type that is too large for the
4881 field. We have to back up by one to find the largest
4883 integer_type = integer_types[itk - 1];
4885 /* Figure out how much additional padding is required. GCC
4886 3.2 always created a padding field, even if it had zero
4888 if (!abi_version_at_least (2)
4889 || INT_CST_LT (TYPE_SIZE (integer_type), DECL_SIZE (field)))
4891 if (abi_version_at_least (2) && TREE_CODE (t) == UNION_TYPE)
4892 /* In a union, the padding field must have the full width
4893 of the bit-field; all fields start at offset zero. */
4894 padding = DECL_SIZE (field);
4897 if (TREE_CODE (t) == UNION_TYPE)
4898 warning (OPT_Wabi, "size assigned to %qT may not be "
4899 "ABI-compliant and may change in a future "
4902 padding = size_binop (MINUS_EXPR, DECL_SIZE (field),
4903 TYPE_SIZE (integer_type));
4906 #ifdef PCC_BITFIELD_TYPE_MATTERS
4907 /* An unnamed bitfield does not normally affect the
4908 alignment of the containing class on a target where
4909 PCC_BITFIELD_TYPE_MATTERS. But, the C++ ABI does not
4910 make any exceptions for unnamed bitfields when the
4911 bitfields are longer than their types. Therefore, we
4912 temporarily give the field a name. */
4913 if (PCC_BITFIELD_TYPE_MATTERS && !DECL_NAME (field))
4915 was_unnamed_p = true;
4916 DECL_NAME (field) = make_anon_name ();
4919 DECL_SIZE (field) = TYPE_SIZE (integer_type);
4920 DECL_ALIGN (field) = TYPE_ALIGN (integer_type);
4921 DECL_USER_ALIGN (field) = TYPE_USER_ALIGN (integer_type);
4922 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4923 empty_base_offsets);
4925 DECL_NAME (field) = NULL_TREE;
4926 /* Now that layout has been performed, set the size of the
4927 field to the size of its declared type; the rest of the
4928 field is effectively invisible. */
4929 DECL_SIZE (field) = TYPE_SIZE (type);
4930 /* We must also reset the DECL_MODE of the field. */
4931 if (abi_version_at_least (2))
4932 DECL_MODE (field) = TYPE_MODE (type);
4934 && DECL_MODE (field) != TYPE_MODE (type))
4935 /* Versions of G++ before G++ 3.4 did not reset the
4938 "the offset of %qD may not be ABI-compliant and may "
4939 "change in a future version of GCC", field);
4942 layout_nonempty_base_or_field (rli, field, NULL_TREE,
4943 empty_base_offsets);
4945 /* Remember the location of any empty classes in FIELD. */
4946 if (abi_version_at_least (2))
4947 record_subobject_offsets (TREE_TYPE (field),
4948 byte_position(field),
4950 /*is_data_member=*/true);
4952 /* If a bit-field does not immediately follow another bit-field,
4953 and yet it starts in the middle of a byte, we have failed to
4954 comply with the ABI. */
4956 && DECL_C_BIT_FIELD (field)
4957 /* The TREE_NO_WARNING flag gets set by Objective-C when
4958 laying out an Objective-C class. The ObjC ABI differs
4959 from the C++ ABI, and so we do not want a warning
4961 && !TREE_NO_WARNING (field)
4962 && !last_field_was_bitfield
4963 && !integer_zerop (size_binop (TRUNC_MOD_EXPR,
4964 DECL_FIELD_BIT_OFFSET (field),
4965 bitsize_unit_node)))
4966 warning (OPT_Wabi, "offset of %q+D is not ABI-compliant and may "
4967 "change in a future version of GCC", field);
4969 /* G++ used to use DECL_FIELD_OFFSET as if it were the byte
4970 offset of the field. */
4972 && !tree_int_cst_equal (DECL_FIELD_OFFSET (field),
4973 byte_position (field))
4974 && contains_empty_class_p (TREE_TYPE (field)))
4975 warning (OPT_Wabi, "%q+D contains empty classes which may cause base "
4976 "classes to be placed at different locations in a "
4977 "future version of GCC", field);
4979 /* The middle end uses the type of expressions to determine the
4980 possible range of expression values. In order to optimize
4981 "x.i > 7" to "false" for a 2-bit bitfield "i", the middle end
4982 must be made aware of the width of "i", via its type.
4984 Because C++ does not have integer types of arbitrary width,
4985 we must (for the purposes of the front end) convert from the
4986 type assigned here to the declared type of the bitfield
4987 whenever a bitfield expression is used as an rvalue.
4988 Similarly, when assigning a value to a bitfield, the value
4989 must be converted to the type given the bitfield here. */
4990 if (DECL_C_BIT_FIELD (field))
4992 unsigned HOST_WIDE_INT width;
4993 tree ftype = TREE_TYPE (field);
4994 width = tree_low_cst (DECL_SIZE (field), /*unsignedp=*/1);
4995 if (width != TYPE_PRECISION (ftype))
4998 = c_build_bitfield_integer_type (width,
4999 TYPE_UNSIGNED (ftype));
5001 = cp_build_qualified_type (TREE_TYPE (field),
5002 TYPE_QUALS (ftype));
5006 /* If we needed additional padding after this field, add it
5012 padding_field = build_decl (FIELD_DECL,
5015 DECL_BIT_FIELD (padding_field) = 1;
5016 DECL_SIZE (padding_field) = padding;
5017 DECL_CONTEXT (padding_field) = t;
5018 DECL_ARTIFICIAL (padding_field) = 1;
5019 DECL_IGNORED_P (padding_field) = 1;
5020 layout_nonempty_base_or_field (rli, padding_field,
5022 empty_base_offsets);
5025 last_field_was_bitfield = DECL_C_BIT_FIELD (field);
5028 if (abi_version_at_least (2) && !integer_zerop (rli->bitpos))
5030 /* Make sure that we are on a byte boundary so that the size of
5031 the class without virtual bases will always be a round number
5033 rli->bitpos = round_up (rli->bitpos, BITS_PER_UNIT);
5034 normalize_rli (rli);
5037 /* G++ 3.2 does not allow virtual bases to be overlaid with tail
5039 if (!abi_version_at_least (2))
5040 include_empty_classes(rli);
5042 /* Delete all zero-width bit-fields from the list of fields. Now
5043 that the type is laid out they are no longer important. */
5044 remove_zero_width_bit_fields (t);
5046 /* Create the version of T used for virtual bases. We do not use
5047 make_class_type for this version; this is an artificial type. For
5048 a POD type, we just reuse T. */
5049 if (CLASSTYPE_NON_POD_P (t) || CLASSTYPE_EMPTY_P (t))
5051 base_t = make_node (TREE_CODE (t));
5053 /* Set the size and alignment for the new type. In G++ 3.2, all
5054 empty classes were considered to have size zero when used as
5056 if (!abi_version_at_least (2) && CLASSTYPE_EMPTY_P (t))
5058 TYPE_SIZE (base_t) = bitsize_zero_node;
5059 TYPE_SIZE_UNIT (base_t) = size_zero_node;
5060 if (warn_abi && !integer_zerop (rli_size_unit_so_far (rli)))
5062 "layout of classes derived from empty class %qT "
5063 "may change in a future version of GCC",
5070 /* If the ABI version is not at least two, and the last
5071 field was a bit-field, RLI may not be on a byte
5072 boundary. In particular, rli_size_unit_so_far might
5073 indicate the last complete byte, while rli_size_so_far
5074 indicates the total number of bits used. Therefore,
5075 rli_size_so_far, rather than rli_size_unit_so_far, is
5076 used to compute TYPE_SIZE_UNIT. */
5077 eoc = end_of_class (t, /*include_virtuals_p=*/0);
5078 TYPE_SIZE_UNIT (base_t)
5079 = size_binop (MAX_EXPR,
5081 size_binop (CEIL_DIV_EXPR,
5082 rli_size_so_far (rli),
5083 bitsize_int (BITS_PER_UNIT))),
5086 = size_binop (MAX_EXPR,
5087 rli_size_so_far (rli),
5088 size_binop (MULT_EXPR,
5089 convert (bitsizetype, eoc),
5090 bitsize_int (BITS_PER_UNIT)));
5092 TYPE_ALIGN (base_t) = rli->record_align;
5093 TYPE_USER_ALIGN (base_t) = TYPE_USER_ALIGN (t);
5095 /* Copy the fields from T. */
5096 next_field = &TYPE_FIELDS (base_t);
5097 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5098 if (TREE_CODE (field) == FIELD_DECL)
5100 *next_field = build_decl (FIELD_DECL,
5103 DECL_CONTEXT (*next_field) = base_t;
5104 DECL_FIELD_OFFSET (*next_field) = DECL_FIELD_OFFSET (field);
5105 DECL_FIELD_BIT_OFFSET (*next_field)
5106 = DECL_FIELD_BIT_OFFSET (field);
5107 DECL_SIZE (*next_field) = DECL_SIZE (field);
5108 DECL_MODE (*next_field) = DECL_MODE (field);
5109 next_field = &TREE_CHAIN (*next_field);
5112 /* Record the base version of the type. */
5113 CLASSTYPE_AS_BASE (t) = base_t;
5114 TYPE_CONTEXT (base_t) = t;
5117 CLASSTYPE_AS_BASE (t) = t;
5119 /* Every empty class contains an empty class. */
5120 if (CLASSTYPE_EMPTY_P (t))
5121 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 1;
5123 /* Set the TYPE_DECL for this type to contain the right
5124 value for DECL_OFFSET, so that we can use it as part
5125 of a COMPONENT_REF for multiple inheritance. */
5126 layout_decl (TYPE_MAIN_DECL (t), 0);
5128 /* Now fix up any virtual base class types that we left lying
5129 around. We must get these done before we try to lay out the
5130 virtual function table. As a side-effect, this will remove the
5131 base subobject fields. */
5132 layout_virtual_bases (rli, empty_base_offsets);
5134 /* Make sure that empty classes are reflected in RLI at this
5136 include_empty_classes(rli);
5138 /* Make sure not to create any structures with zero size. */
5139 if (integer_zerop (rli_size_unit_so_far (rli)) && CLASSTYPE_EMPTY_P (t))
5141 build_decl (FIELD_DECL, NULL_TREE, char_type_node));
5143 /* Let the back end lay out the type. */
5144 finish_record_layout (rli, /*free_p=*/true);
5146 /* Warn about bases that can't be talked about due to ambiguity. */
5147 warn_about_ambiguous_bases (t);
5149 /* Now that we're done with layout, give the base fields the real types. */
5150 for (field = TYPE_FIELDS (t); field; field = TREE_CHAIN (field))
5151 if (DECL_ARTIFICIAL (field) && IS_FAKE_BASE_TYPE (TREE_TYPE (field)))
5152 TREE_TYPE (field) = TYPE_CONTEXT (TREE_TYPE (field));
5155 splay_tree_delete (empty_base_offsets);
5157 if (CLASSTYPE_EMPTY_P (t)
5158 && tree_int_cst_lt (sizeof_biggest_empty_class,
5159 TYPE_SIZE_UNIT (t)))
5160 sizeof_biggest_empty_class = TYPE_SIZE_UNIT (t);
5163 /* Determine the "key method" for the class type indicated by TYPE,
5164 and set CLASSTYPE_KEY_METHOD accordingly. */
5167 determine_key_method (tree type)
5171 if (TYPE_FOR_JAVA (type)
5172 || processing_template_decl
5173 || CLASSTYPE_TEMPLATE_INSTANTIATION (type)
5174 || CLASSTYPE_INTERFACE_KNOWN (type))
5177 /* The key method is the first non-pure virtual function that is not
5178 inline at the point of class definition. On some targets the
5179 key function may not be inline; those targets should not call
5180 this function until the end of the translation unit. */
5181 for (method = TYPE_METHODS (type); method != NULL_TREE;
5182 method = TREE_CHAIN (method))
5183 if (DECL_VINDEX (method) != NULL_TREE
5184 && ! DECL_DECLARED_INLINE_P (method)
5185 && ! DECL_PURE_VIRTUAL_P (method))
5187 CLASSTYPE_KEY_METHOD (type) = method;
5194 /* Perform processing required when the definition of T (a class type)
5198 finish_struct_1 (tree t)
5201 /* A TREE_LIST. The TREE_VALUE of each node is a FUNCTION_DECL. */
5202 tree virtuals = NULL_TREE;
5205 if (COMPLETE_TYPE_P (t))
5207 gcc_assert (MAYBE_CLASS_TYPE_P (t));
5208 error ("redefinition of %q#T", t);
5213 /* If this type was previously laid out as a forward reference,
5214 make sure we lay it out again. */
5215 TYPE_SIZE (t) = NULL_TREE;
5216 CLASSTYPE_PRIMARY_BINFO (t) = NULL_TREE;
5218 fixup_inline_methods (t);
5220 /* Make assumptions about the class; we'll reset the flags if
5222 CLASSTYPE_EMPTY_P (t) = 1;
5223 CLASSTYPE_NEARLY_EMPTY_P (t) = 1;
5224 CLASSTYPE_CONTAINS_EMPTY_CLASS_P (t) = 0;
5226 /* Do end-of-class semantic processing: checking the validity of the
5227 bases and members and add implicitly generated methods. */
5228 check_bases_and_members (t);
5230 /* Find the key method. */
5231 if (TYPE_CONTAINS_VPTR_P (t))
5233 /* The Itanium C++ ABI permits the key method to be chosen when
5234 the class is defined -- even though the key method so
5235 selected may later turn out to be an inline function. On
5236 some systems (such as ARM Symbian OS) the key method cannot
5237 be determined until the end of the translation unit. On such
5238 systems, we leave CLASSTYPE_KEY_METHOD set to NULL, which
5239 will cause the class to be added to KEYED_CLASSES. Then, in
5240 finish_file we will determine the key method. */
5241 if (targetm.cxx.key_method_may_be_inline ())
5242 determine_key_method (t);
5244 /* If a polymorphic class has no key method, we may emit the vtable
5245 in every translation unit where the class definition appears. */
5246 if (CLASSTYPE_KEY_METHOD (t) == NULL_TREE)
5247 keyed_classes = tree_cons (NULL_TREE, t, keyed_classes);
5250 /* Layout the class itself. */
5251 layout_class_type (t, &virtuals);
5252 if (CLASSTYPE_AS_BASE (t) != t)
5253 /* We use the base type for trivial assignments, and hence it
5255 compute_record_mode (CLASSTYPE_AS_BASE (t));
5257 virtuals = modify_all_vtables (t, nreverse (virtuals));
5259 /* If necessary, create the primary vtable for this class. */
5260 if (virtuals || TYPE_CONTAINS_VPTR_P (t))
5262 /* We must enter these virtuals into the table. */
5263 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5264 build_primary_vtable (NULL_TREE, t);
5265 else if (! BINFO_NEW_VTABLE_MARKED (TYPE_BINFO (t)))
5266 /* Here we know enough to change the type of our virtual
5267 function table, but we will wait until later this function. */
5268 build_primary_vtable (CLASSTYPE_PRIMARY_BINFO (t), t);
5271 if (TYPE_CONTAINS_VPTR_P (t))
5276 if (BINFO_VTABLE (TYPE_BINFO (t)))
5277 gcc_assert (DECL_VIRTUAL_P (BINFO_VTABLE (TYPE_BINFO (t))));
5278 if (!CLASSTYPE_HAS_PRIMARY_BASE_P (t))
5279 gcc_assert (BINFO_VIRTUALS (TYPE_BINFO (t)) == NULL_TREE);
5281 /* Add entries for virtual functions introduced by this class. */
5282 BINFO_VIRTUALS (TYPE_BINFO (t))
5283 = chainon (BINFO_VIRTUALS (TYPE_BINFO (t)), virtuals);
5285 /* Set DECL_VINDEX for all functions declared in this class. */
5286 for (vindex = 0, fn = BINFO_VIRTUALS (TYPE_BINFO (t));
5288 fn = TREE_CHAIN (fn),
5289 vindex += (TARGET_VTABLE_USES_DESCRIPTORS
5290 ? TARGET_VTABLE_USES_DESCRIPTORS : 1))
5292 tree fndecl = BV_FN (fn);
5294 if (DECL_THUNK_P (fndecl))
5295 /* A thunk. We should never be calling this entry directly
5296 from this vtable -- we'd use the entry for the non
5297 thunk base function. */
5298 DECL_VINDEX (fndecl) = NULL_TREE;
5299 else if (TREE_CODE (DECL_VINDEX (fndecl)) != INTEGER_CST)
5300 DECL_VINDEX (fndecl) = build_int_cst (NULL_TREE, vindex);
5304 finish_struct_bits (t);
5306 /* Complete the rtl for any static member objects of the type we're
5308 for (x = TYPE_FIELDS (t); x; x = TREE_CHAIN (x))
5309 if (TREE_CODE (x) == VAR_DECL && TREE_STATIC (x)
5310 && TREE_TYPE (x) != error_mark_node
5311 && same_type_p (TYPE_MAIN_VARIANT (TREE_TYPE (x)), t))
5312 DECL_MODE (x) = TYPE_MODE (t);
5314 /* Done with FIELDS...now decide whether to sort these for
5315 faster lookups later.
5317 We use a small number because most searches fail (succeeding
5318 ultimately as the search bores through the inheritance
5319 hierarchy), and we want this failure to occur quickly. */
5321 n_fields = count_fields (TYPE_FIELDS (t));
5324 struct sorted_fields_type *field_vec = GGC_NEWVAR
5325 (struct sorted_fields_type,
5326 sizeof (struct sorted_fields_type) + n_fields * sizeof (tree));
5327 field_vec->len = n_fields;
5328 add_fields_to_record_type (TYPE_FIELDS (t), field_vec, 0);
5329 qsort (field_vec->elts, n_fields, sizeof (tree),
5331 if (! DECL_LANG_SPECIFIC (TYPE_MAIN_DECL (t)))
5332 retrofit_lang_decl (TYPE_MAIN_DECL (t));
5333 DECL_SORTED_FIELDS (TYPE_MAIN_DECL (t)) = field_vec;
5336 /* Complain if one of the field types requires lower visibility. */
5337 constrain_class_visibility (t);
5339 /* Make the rtl for any new vtables we have created, and unmark
5340 the base types we marked. */
5343 /* Build the VTT for T. */
5346 /* This warning does not make sense for Java classes, since they
5347 cannot have destructors. */
5348 if (!TYPE_FOR_JAVA (t) && warn_nonvdtor && TYPE_POLYMORPHIC_P (t))
5352 dtor = CLASSTYPE_DESTRUCTORS (t);
5353 if (/* An implicitly declared destructor is always public. And,
5354 if it were virtual, we would have created it by now. */
5356 || (!DECL_VINDEX (dtor)
5357 && (/* public non-virtual */
5358 (!TREE_PRIVATE (dtor) && !TREE_PROTECTED (dtor))
5359 || (/* non-public non-virtual with friends */
5360 (TREE_PRIVATE (dtor) || TREE_PROTECTED (dtor))
5361 && (CLASSTYPE_FRIEND_CLASSES (t)
5362 || DECL_FRIENDLIST (TYPE_MAIN_DECL (t)))))))
5363 warning (OPT_Wnon_virtual_dtor,
5364 "%q#T has virtual functions and accessible"
5365 " non-virtual destructor", t);
5370 if (warn_overloaded_virtual)
5373 /* Class layout, assignment of virtual table slots, etc., is now
5374 complete. Give the back end a chance to tweak the visibility of
5375 the class or perform any other required target modifications. */
5376 targetm.cxx.adjust_class_at_definition (t);
5378 maybe_suppress_debug_info (t);
5380 dump_class_hierarchy (t);
5382 /* Finish debugging output for this type. */
5383 rest_of_type_compilation (t, ! LOCAL_CLASS_P (t));
5386 /* When T was built up, the member declarations were added in reverse
5387 order. Rearrange them to declaration order. */
5390 unreverse_member_declarations (tree t)
5396 /* The following lists are all in reverse order. Put them in
5397 declaration order now. */
5398 TYPE_METHODS (t) = nreverse (TYPE_METHODS (t));
5399 CLASSTYPE_DECL_LIST (t) = nreverse (CLASSTYPE_DECL_LIST (t));
5401 /* Actually, for the TYPE_FIELDS, only the non TYPE_DECLs are in
5402 reverse order, so we can't just use nreverse. */
5404 for (x = TYPE_FIELDS (t);
5405 x && TREE_CODE (x) != TYPE_DECL;
5408 next = TREE_CHAIN (x);
5409 TREE_CHAIN (x) = prev;
5414 TREE_CHAIN (TYPE_FIELDS (t)) = x;
5416 TYPE_FIELDS (t) = prev;
5421 finish_struct (tree t, tree attributes)
5423 location_t saved_loc = input_location;
5425 /* Now that we've got all the field declarations, reverse everything
5427 unreverse_member_declarations (t);
5429 cplus_decl_attributes (&t, attributes, (int) ATTR_FLAG_TYPE_IN_PLACE);
5431 /* Nadger the current location so that diagnostics point to the start of
5432 the struct, not the end. */
5433 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (t));
5435 if (processing_template_decl)
5439 finish_struct_methods (t);
5440 TYPE_SIZE (t) = bitsize_zero_node;
5441 TYPE_SIZE_UNIT (t) = size_zero_node;
5443 /* We need to emit an error message if this type was used as a parameter
5444 and it is an abstract type, even if it is a template. We construct
5445 a simple CLASSTYPE_PURE_VIRTUALS list without taking bases into
5446 account and we call complete_vars with this type, which will check
5447 the PARM_DECLS. Note that while the type is being defined,
5448 CLASSTYPE_PURE_VIRTUALS contains the list of the inline friends
5449 (see CLASSTYPE_INLINE_FRIENDS) so we need to clear it. */
5450 CLASSTYPE_PURE_VIRTUALS (t) = NULL;
5451 for (x = TYPE_METHODS (t); x; x = TREE_CHAIN (x))
5452 if (DECL_PURE_VIRTUAL_P (x))
5453 VEC_safe_push (tree, gc, CLASSTYPE_PURE_VIRTUALS (t), x);
5457 finish_struct_1 (t);
5459 input_location = saved_loc;
5461 TYPE_BEING_DEFINED (t) = 0;
5463 if (current_class_type)
5466 error ("trying to finish struct, but kicked out due to previous parse errors");
5468 if (processing_template_decl && at_function_scope_p ())
5469 add_stmt (build_min (TAG_DEFN, t));
5474 /* Return the dynamic type of INSTANCE, if known.
5475 Used to determine whether the virtual function table is needed
5478 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5479 of our knowledge of its type. *NONNULL should be initialized
5480 before this function is called. */
5483 fixed_type_or_null (tree instance, int *nonnull, int *cdtorp)
5485 #define RECUR(T) fixed_type_or_null((T), nonnull, cdtorp)
5487 switch (TREE_CODE (instance))
5490 if (POINTER_TYPE_P (TREE_TYPE (instance)))
5493 return RECUR (TREE_OPERAND (instance, 0));
5496 /* This is a call to a constructor, hence it's never zero. */
5497 if (TREE_HAS_CONSTRUCTOR (instance))
5501 return TREE_TYPE (instance);
5506 /* This is a call to a constructor, hence it's never zero. */
5507 if (TREE_HAS_CONSTRUCTOR (instance))
5511 return TREE_TYPE (instance);
5513 return RECUR (TREE_OPERAND (instance, 0));
5515 case POINTER_PLUS_EXPR:
5518 if (TREE_CODE (TREE_OPERAND (instance, 0)) == ADDR_EXPR)
5519 return RECUR (TREE_OPERAND (instance, 0));
5520 if (TREE_CODE (TREE_OPERAND (instance, 1)) == INTEGER_CST)
5521 /* Propagate nonnull. */
5522 return RECUR (TREE_OPERAND (instance, 0));
5527 return RECUR (TREE_OPERAND (instance, 0));
5530 instance = TREE_OPERAND (instance, 0);
5533 /* Just because we see an ADDR_EXPR doesn't mean we're dealing
5534 with a real object -- given &p->f, p can still be null. */
5535 tree t = get_base_address (instance);
5536 /* ??? Probably should check DECL_WEAK here. */
5537 if (t && DECL_P (t))
5540 return RECUR (instance);
5543 /* If this component is really a base class reference, then the field
5544 itself isn't definitive. */
5545 if (DECL_FIELD_IS_BASE (TREE_OPERAND (instance, 1)))
5546 return RECUR (TREE_OPERAND (instance, 0));
5547 return RECUR (TREE_OPERAND (instance, 1));
5551 if (TREE_CODE (TREE_TYPE (instance)) == ARRAY_TYPE
5552 && MAYBE_CLASS_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
5556 return TREE_TYPE (TREE_TYPE (instance));
5558 /* fall through... */
5562 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (instance)))
5566 return TREE_TYPE (instance);
5568 else if (instance == current_class_ptr)
5573 /* if we're in a ctor or dtor, we know our type. */
5574 if (DECL_LANG_SPECIFIC (current_function_decl)
5575 && (DECL_CONSTRUCTOR_P (current_function_decl)
5576 || DECL_DESTRUCTOR_P (current_function_decl)))
5580 return TREE_TYPE (TREE_TYPE (instance));
5583 else if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5585 /* We only need one hash table because it is always left empty. */
5588 ht = htab_create (37,
5593 /* Reference variables should be references to objects. */
5597 /* Enter the INSTANCE in a table to prevent recursion; a
5598 variable's initializer may refer to the variable
5600 if (TREE_CODE (instance) == VAR_DECL
5601 && DECL_INITIAL (instance)
5602 && !htab_find (ht, instance))
5607 slot = htab_find_slot (ht, instance, INSERT);
5609 type = RECUR (DECL_INITIAL (instance));
5610 htab_remove_elt (ht, instance);
5623 /* Return nonzero if the dynamic type of INSTANCE is known, and
5624 equivalent to the static type. We also handle the case where
5625 INSTANCE is really a pointer. Return negative if this is a
5626 ctor/dtor. There the dynamic type is known, but this might not be
5627 the most derived base of the original object, and hence virtual
5628 bases may not be layed out according to this type.
5630 Used to determine whether the virtual function table is needed
5633 *NONNULL is set iff INSTANCE can be known to be nonnull, regardless
5634 of our knowledge of its type. *NONNULL should be initialized
5635 before this function is called. */
5638 resolves_to_fixed_type_p (tree instance, int* nonnull)
5640 tree t = TREE_TYPE (instance);
5642 tree fixed = fixed_type_or_null (instance, nonnull, &cdtorp);
5643 if (fixed == NULL_TREE)
5645 if (POINTER_TYPE_P (t))
5647 if (!same_type_ignoring_top_level_qualifiers_p (t, fixed))
5649 return cdtorp ? -1 : 1;
5654 init_class_processing (void)
5656 current_class_depth = 0;
5657 current_class_stack_size = 10;
5659 = XNEWVEC (struct class_stack_node, current_class_stack_size);
5660 local_classes = VEC_alloc (tree, gc, 8);
5661 sizeof_biggest_empty_class = size_zero_node;
5663 ridpointers[(int) RID_PUBLIC] = access_public_node;
5664 ridpointers[(int) RID_PRIVATE] = access_private_node;
5665 ridpointers[(int) RID_PROTECTED] = access_protected_node;
5668 /* Restore the cached PREVIOUS_CLASS_LEVEL. */
5671 restore_class_cache (void)
5675 /* We are re-entering the same class we just left, so we don't
5676 have to search the whole inheritance matrix to find all the
5677 decls to bind again. Instead, we install the cached
5678 class_shadowed list and walk through it binding names. */
5679 push_binding_level (previous_class_level);
5680 class_binding_level = previous_class_level;
5681 /* Restore IDENTIFIER_TYPE_VALUE. */
5682 for (type = class_binding_level->type_shadowed;
5684 type = TREE_CHAIN (type))
5685 SET_IDENTIFIER_TYPE_VALUE (TREE_PURPOSE (type), TREE_TYPE (type));
5688 /* Set global variables CURRENT_CLASS_NAME and CURRENT_CLASS_TYPE as
5689 appropriate for TYPE.
5691 So that we may avoid calls to lookup_name, we cache the _TYPE
5692 nodes of local TYPE_DECLs in the TREE_TYPE field of the name.
5694 For multiple inheritance, we perform a two-pass depth-first search
5695 of the type lattice. */
5698 pushclass (tree type)
5700 class_stack_node_t csn;
5702 type = TYPE_MAIN_VARIANT (type);
5704 /* Make sure there is enough room for the new entry on the stack. */
5705 if (current_class_depth + 1 >= current_class_stack_size)
5707 current_class_stack_size *= 2;
5709 = XRESIZEVEC (struct class_stack_node, current_class_stack,
5710 current_class_stack_size);
5713 /* Insert a new entry on the class stack. */
5714 csn = current_class_stack + current_class_depth;
5715 csn->name = current_class_name;
5716 csn->type = current_class_type;
5717 csn->access = current_access_specifier;
5718 csn->names_used = 0;
5720 current_class_depth++;
5722 /* Now set up the new type. */
5723 current_class_name = TYPE_NAME (type);
5724 if (TREE_CODE (current_class_name) == TYPE_DECL)
5725 current_class_name = DECL_NAME (current_class_name);
5726 current_class_type = type;
5728 /* By default, things in classes are private, while things in
5729 structures or unions are public. */
5730 current_access_specifier = (CLASSTYPE_DECLARED_CLASS (type)
5731 ? access_private_node
5732 : access_public_node);
5734 if (previous_class_level
5735 && type != previous_class_level->this_entity
5736 && current_class_depth == 1)
5738 /* Forcibly remove any old class remnants. */
5739 invalidate_class_lookup_cache ();
5742 if (!previous_class_level
5743 || type != previous_class_level->this_entity
5744 || current_class_depth > 1)
5747 restore_class_cache ();
5750 /* When we exit a toplevel class scope, we save its binding level so
5751 that we can restore it quickly. Here, we've entered some other
5752 class, so we must invalidate our cache. */
5755 invalidate_class_lookup_cache (void)
5757 previous_class_level = NULL;
5760 /* Get out of the current class scope. If we were in a class scope
5761 previously, that is the one popped to. */
5768 current_class_depth--;
5769 current_class_name = current_class_stack[current_class_depth].name;
5770 current_class_type = current_class_stack[current_class_depth].type;
5771 current_access_specifier = current_class_stack[current_class_depth].access;
5772 if (current_class_stack[current_class_depth].names_used)
5773 splay_tree_delete (current_class_stack[current_class_depth].names_used);
5776 /* Mark the top of the class stack as hidden. */
5779 push_class_stack (void)
5781 if (current_class_depth)
5782 ++current_class_stack[current_class_depth - 1].hidden;
5785 /* Mark the top of the class stack as un-hidden. */
5788 pop_class_stack (void)
5790 if (current_class_depth)
5791 --current_class_stack[current_class_depth - 1].hidden;
5794 /* Returns 1 if the class type currently being defined is either T or
5795 a nested type of T. */
5798 currently_open_class (tree t)
5802 if (!CLASS_TYPE_P (t))
5805 /* We start looking from 1 because entry 0 is from global scope,
5807 for (i = current_class_depth; i > 0; --i)
5810 if (i == current_class_depth)
5811 c = current_class_type;
5814 if (current_class_stack[i].hidden)
5816 c = current_class_stack[i].type;
5820 if (same_type_p (c, t))
5826 /* If either current_class_type or one of its enclosing classes are derived
5827 from T, return the appropriate type. Used to determine how we found
5828 something via unqualified lookup. */
5831 currently_open_derived_class (tree t)
5835 /* The bases of a dependent type are unknown. */
5836 if (dependent_type_p (t))
5839 if (!current_class_type)
5842 if (DERIVED_FROM_P (t, current_class_type))
5843 return current_class_type;
5845 for (i = current_class_depth - 1; i > 0; --i)
5847 if (current_class_stack[i].hidden)
5849 if (DERIVED_FROM_P (t, current_class_stack[i].type))
5850 return current_class_stack[i].type;
5856 /* When entering a class scope, all enclosing class scopes' names with
5857 static meaning (static variables, static functions, types and
5858 enumerators) have to be visible. This recursive function calls
5859 pushclass for all enclosing class contexts until global or a local
5860 scope is reached. TYPE is the enclosed class. */
5863 push_nested_class (tree type)
5865 /* A namespace might be passed in error cases, like A::B:C. */
5866 if (type == NULL_TREE
5867 || !CLASS_TYPE_P (type))
5870 push_nested_class (DECL_CONTEXT (TYPE_MAIN_DECL (type)));
5875 /* Undoes a push_nested_class call. */
5878 pop_nested_class (void)
5880 tree context = DECL_CONTEXT (TYPE_MAIN_DECL (current_class_type));
5883 if (context && CLASS_TYPE_P (context))
5884 pop_nested_class ();
5887 /* Returns the number of extern "LANG" blocks we are nested within. */
5890 current_lang_depth (void)
5892 return VEC_length (tree, current_lang_base);
5895 /* Set global variables CURRENT_LANG_NAME to appropriate value
5896 so that behavior of name-mangling machinery is correct. */
5899 push_lang_context (tree name)
5901 VEC_safe_push (tree, gc, current_lang_base, current_lang_name);
5903 if (name == lang_name_cplusplus)
5905 current_lang_name = name;
5907 else if (name == lang_name_java)
5909 current_lang_name = name;
5910 /* DECL_IGNORED_P is initially set for these types, to avoid clutter.
5911 (See record_builtin_java_type in decl.c.) However, that causes
5912 incorrect debug entries if these types are actually used.
5913 So we re-enable debug output after extern "Java". */
5914 DECL_IGNORED_P (TYPE_NAME (java_byte_type_node)) = 0;
5915 DECL_IGNORED_P (TYPE_NAME (java_short_type_node)) = 0;
5916 DECL_IGNORED_P (TYPE_NAME (java_int_type_node)) = 0;
5917 DECL_IGNORED_P (TYPE_NAME (java_long_type_node)) = 0;
5918 DECL_IGNORED_P (TYPE_NAME (java_float_type_node)) = 0;
5919 DECL_IGNORED_P (TYPE_NAME (java_double_type_node)) = 0;
5920 DECL_IGNORED_P (TYPE_NAME (java_char_type_node)) = 0;
5921 DECL_IGNORED_P (TYPE_NAME (java_boolean_type_node)) = 0;
5923 else if (name == lang_name_c)
5925 current_lang_name = name;
5928 error ("language string %<\"%E\"%> not recognized", name);
5931 /* Get out of the current language scope. */
5934 pop_lang_context (void)
5936 current_lang_name = VEC_pop (tree, current_lang_base);
5939 /* Type instantiation routines. */
5941 /* Given an OVERLOAD and a TARGET_TYPE, return the function that
5942 matches the TARGET_TYPE. If there is no satisfactory match, return
5943 error_mark_node, and issue an error & warning messages under
5944 control of FLAGS. Permit pointers to member function if FLAGS
5945 permits. If TEMPLATE_ONLY, the name of the overloaded function was
5946 a template-id, and EXPLICIT_TARGS are the explicitly provided
5949 If OVERLOAD is for one or more member functions, then ACCESS_PATH
5950 is the base path used to reference those member functions. If
5951 TF_NO_ACCESS_CONTROL is not set in FLAGS, and the address is
5952 resolved to a member function, access checks will be performed and
5953 errors issued if appropriate. */
5956 resolve_address_of_overloaded_function (tree target_type,
5958 tsubst_flags_t flags,
5960 tree explicit_targs,
5963 /* Here's what the standard says:
5967 If the name is a function template, template argument deduction
5968 is done, and if the argument deduction succeeds, the deduced
5969 arguments are used to generate a single template function, which
5970 is added to the set of overloaded functions considered.
5972 Non-member functions and static member functions match targets of
5973 type "pointer-to-function" or "reference-to-function." Nonstatic
5974 member functions match targets of type "pointer-to-member
5975 function;" the function type of the pointer to member is used to
5976 select the member function from the set of overloaded member
5977 functions. If a nonstatic member function is selected, the
5978 reference to the overloaded function name is required to have the
5979 form of a pointer to member as described in 5.3.1.
5981 If more than one function is selected, any template functions in
5982 the set are eliminated if the set also contains a non-template
5983 function, and any given template function is eliminated if the
5984 set contains a second template function that is more specialized
5985 than the first according to the partial ordering rules 14.5.5.2.
5986 After such eliminations, if any, there shall remain exactly one
5987 selected function. */
5990 int is_reference = 0;
5991 /* We store the matches in a TREE_LIST rooted here. The functions
5992 are the TREE_PURPOSE, not the TREE_VALUE, in this list, for easy
5993 interoperability with most_specialized_instantiation. */
5994 tree matches = NULL_TREE;
5997 /* By the time we get here, we should be seeing only real
5998 pointer-to-member types, not the internal POINTER_TYPE to
5999 METHOD_TYPE representation. */
6000 gcc_assert (TREE_CODE (target_type) != POINTER_TYPE
6001 || TREE_CODE (TREE_TYPE (target_type)) != METHOD_TYPE);
6003 gcc_assert (is_overloaded_fn (overload));
6005 /* Check that the TARGET_TYPE is reasonable. */
6006 if (TYPE_PTRFN_P (target_type))
6008 else if (TYPE_PTRMEMFUNC_P (target_type))
6009 /* This is OK, too. */
6011 else if (TREE_CODE (target_type) == FUNCTION_TYPE)
6013 /* This is OK, too. This comes from a conversion to reference
6015 target_type = build_reference_type (target_type);
6020 if (flags & tf_error)
6021 error ("cannot resolve overloaded function %qD based on"
6022 " conversion to type %qT",
6023 DECL_NAME (OVL_FUNCTION (overload)), target_type);
6024 return error_mark_node;
6027 /* If we can find a non-template function that matches, we can just
6028 use it. There's no point in generating template instantiations
6029 if we're just going to throw them out anyhow. But, of course, we
6030 can only do this when we don't *need* a template function. */
6035 for (fns = overload; fns; fns = OVL_NEXT (fns))
6037 tree fn = OVL_CURRENT (fns);
6040 if (TREE_CODE (fn) == TEMPLATE_DECL)
6041 /* We're not looking for templates just yet. */
6044 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6046 /* We're looking for a non-static member, and this isn't
6047 one, or vice versa. */
6050 /* Ignore functions which haven't been explicitly
6052 if (DECL_ANTICIPATED (fn))
6055 /* See if there's a match. */
6056 fntype = TREE_TYPE (fn);
6058 fntype = build_ptrmemfunc_type (build_pointer_type (fntype));
6059 else if (!is_reference)
6060 fntype = build_pointer_type (fntype);
6062 if (can_convert_arg (target_type, fntype, fn, LOOKUP_NORMAL))
6063 matches = tree_cons (fn, NULL_TREE, matches);
6067 /* Now, if we've already got a match (or matches), there's no need
6068 to proceed to the template functions. But, if we don't have a
6069 match we need to look at them, too. */
6072 tree target_fn_type;
6073 tree target_arg_types;
6074 tree target_ret_type;
6079 = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (target_type));
6081 target_fn_type = TREE_TYPE (target_type);
6082 target_arg_types = TYPE_ARG_TYPES (target_fn_type);
6083 target_ret_type = TREE_TYPE (target_fn_type);
6085 /* Never do unification on the 'this' parameter. */
6086 if (TREE_CODE (target_fn_type) == METHOD_TYPE)
6087 target_arg_types = TREE_CHAIN (target_arg_types);
6089 for (fns = overload; fns; fns = OVL_NEXT (fns))
6091 tree fn = OVL_CURRENT (fns);
6093 tree instantiation_type;
6096 if (TREE_CODE (fn) != TEMPLATE_DECL)
6097 /* We're only looking for templates. */
6100 if ((TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6102 /* We're not looking for a non-static member, and this is
6103 one, or vice versa. */
6106 /* Try to do argument deduction. */
6107 targs = make_tree_vec (DECL_NTPARMS (fn));
6108 if (fn_type_unification (fn, explicit_targs, targs,
6109 target_arg_types, target_ret_type,
6110 DEDUCE_EXACT, LOOKUP_NORMAL))
6111 /* Argument deduction failed. */
6114 /* Instantiate the template. */
6115 instantiation = instantiate_template (fn, targs, flags);
6116 if (instantiation == error_mark_node)
6117 /* Instantiation failed. */
6120 /* See if there's a match. */
6121 instantiation_type = TREE_TYPE (instantiation);
6123 instantiation_type =
6124 build_ptrmemfunc_type (build_pointer_type (instantiation_type));
6125 else if (!is_reference)
6126 instantiation_type = build_pointer_type (instantiation_type);
6127 if (can_convert_arg (target_type, instantiation_type, instantiation,
6129 matches = tree_cons (instantiation, fn, matches);
6132 /* Now, remove all but the most specialized of the matches. */
6135 tree match = most_specialized_instantiation (matches);
6137 if (match != error_mark_node)
6138 matches = tree_cons (TREE_PURPOSE (match),
6144 /* Now we should have exactly one function in MATCHES. */
6145 if (matches == NULL_TREE)
6147 /* There were *no* matches. */
6148 if (flags & tf_error)
6150 error ("no matches converting function %qD to type %q#T",
6151 DECL_NAME (OVL_FUNCTION (overload)),
6154 /* print_candidates expects a chain with the functions in
6155 TREE_VALUE slots, so we cons one up here (we're losing anyway,
6156 so why be clever?). */
6157 for (; overload; overload = OVL_NEXT (overload))
6158 matches = tree_cons (NULL_TREE, OVL_CURRENT (overload),
6161 print_candidates (matches);
6163 return error_mark_node;
6165 else if (TREE_CHAIN (matches))
6167 /* There were too many matches. First check if they're all
6168 the same function. */
6171 fn = TREE_PURPOSE (matches);
6172 for (match = TREE_CHAIN (matches); match; match = TREE_CHAIN (match))
6173 if (!decls_match (fn, TREE_PURPOSE (matches)))
6178 if (flags & tf_error)
6180 error ("converting overloaded function %qD to type %q#T is ambiguous",
6181 DECL_NAME (OVL_FUNCTION (overload)),
6184 /* Since print_candidates expects the functions in the
6185 TREE_VALUE slot, we flip them here. */
6186 for (match = matches; match; match = TREE_CHAIN (match))
6187 TREE_VALUE (match) = TREE_PURPOSE (match);
6189 print_candidates (matches);
6192 return error_mark_node;
6196 /* Good, exactly one match. Now, convert it to the correct type. */
6197 fn = TREE_PURPOSE (matches);
6199 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
6200 && !(flags & tf_ptrmem_ok) && !flag_ms_extensions)
6202 static int explained;
6204 if (!(flags & tf_error))
6205 return error_mark_node;
6207 permerror (input_location, "assuming pointer to member %qD", fn);
6210 inform (input_location, "(a pointer to member can only be formed with %<&%E%>)", fn);
6215 /* If we're doing overload resolution purely for the purpose of
6216 determining conversion sequences, we should not consider the
6217 function used. If this conversion sequence is selected, the
6218 function will be marked as used at this point. */
6219 if (!(flags & tf_conv))
6221 /* Make =delete work with SFINAE. */
6222 if (DECL_DELETED_FN (fn) && !(flags & tf_error))
6223 return error_mark_node;
6228 /* We could not check access to member functions when this
6229 expression was originally created since we did not know at that
6230 time to which function the expression referred. */
6231 if (!(flags & tf_no_access_control)
6232 && DECL_FUNCTION_MEMBER_P (fn))
6234 gcc_assert (access_path);
6235 perform_or_defer_access_check (access_path, fn, fn);
6238 if (TYPE_PTRFN_P (target_type) || TYPE_PTRMEMFUNC_P (target_type))
6239 return cp_build_unary_op (ADDR_EXPR, fn, 0, flags);
6242 /* The target must be a REFERENCE_TYPE. Above, cp_build_unary_op
6243 will mark the function as addressed, but here we must do it
6245 cxx_mark_addressable (fn);
6251 /* This function will instantiate the type of the expression given in
6252 RHS to match the type of LHSTYPE. If errors exist, then return
6253 error_mark_node. FLAGS is a bit mask. If TF_ERROR is set, then
6254 we complain on errors. If we are not complaining, never modify rhs,
6255 as overload resolution wants to try many possible instantiations, in
6256 the hope that at least one will work.
6258 For non-recursive calls, LHSTYPE should be a function, pointer to
6259 function, or a pointer to member function. */
6262 instantiate_type (tree lhstype, tree rhs, tsubst_flags_t flags)
6264 tsubst_flags_t flags_in = flags;
6265 tree access_path = NULL_TREE;
6267 flags &= ~tf_ptrmem_ok;
6269 if (TREE_CODE (lhstype) == UNKNOWN_TYPE)
6271 if (flags & tf_error)
6272 error ("not enough type information");
6273 return error_mark_node;
6276 if (TREE_TYPE (rhs) != NULL_TREE && ! (type_unknown_p (rhs)))
6278 if (same_type_p (lhstype, TREE_TYPE (rhs)))
6280 if (flag_ms_extensions
6281 && TYPE_PTRMEMFUNC_P (lhstype)
6282 && !TYPE_PTRMEMFUNC_P (TREE_TYPE (rhs)))
6283 /* Microsoft allows `A::f' to be resolved to a
6284 pointer-to-member. */
6288 if (flags & tf_error)
6289 error ("argument of type %qT does not match %qT",
6290 TREE_TYPE (rhs), lhstype);
6291 return error_mark_node;
6295 if (TREE_CODE (rhs) == BASELINK)
6297 access_path = BASELINK_ACCESS_BINFO (rhs);
6298 rhs = BASELINK_FUNCTIONS (rhs);
6301 /* If we are in a template, and have a NON_DEPENDENT_EXPR, we cannot
6302 deduce any type information. */
6303 if (TREE_CODE (rhs) == NON_DEPENDENT_EXPR)
6305 if (flags & tf_error)
6306 error ("not enough type information");
6307 return error_mark_node;
6310 /* There only a few kinds of expressions that may have a type
6311 dependent on overload resolution. */
6312 gcc_assert (TREE_CODE (rhs) == ADDR_EXPR
6313 || TREE_CODE (rhs) == COMPONENT_REF
6314 || TREE_CODE (rhs) == COMPOUND_EXPR
6315 || really_overloaded_fn (rhs));
6317 /* We don't overwrite rhs if it is an overloaded function.
6318 Copying it would destroy the tree link. */
6319 if (TREE_CODE (rhs) != OVERLOAD)
6320 rhs = copy_node (rhs);
6322 /* This should really only be used when attempting to distinguish
6323 what sort of a pointer to function we have. For now, any
6324 arithmetic operation which is not supported on pointers
6325 is rejected as an error. */
6327 switch (TREE_CODE (rhs))
6331 tree member = TREE_OPERAND (rhs, 1);
6333 member = instantiate_type (lhstype, member, flags);
6334 if (member != error_mark_node
6335 && TREE_SIDE_EFFECTS (TREE_OPERAND (rhs, 0)))
6336 /* Do not lose object's side effects. */
6337 return build2 (COMPOUND_EXPR, TREE_TYPE (member),
6338 TREE_OPERAND (rhs, 0), member);
6343 rhs = TREE_OPERAND (rhs, 1);
6344 if (BASELINK_P (rhs))
6345 return instantiate_type (lhstype, rhs, flags_in);
6347 /* This can happen if we are forming a pointer-to-member for a
6349 gcc_assert (TREE_CODE (rhs) == TEMPLATE_ID_EXPR);
6353 case TEMPLATE_ID_EXPR:
6355 tree fns = TREE_OPERAND (rhs, 0);
6356 tree args = TREE_OPERAND (rhs, 1);
6359 resolve_address_of_overloaded_function (lhstype, fns, flags_in,
6360 /*template_only=*/true,
6367 resolve_address_of_overloaded_function (lhstype, rhs, flags_in,
6368 /*template_only=*/false,
6369 /*explicit_targs=*/NULL_TREE,
6373 TREE_OPERAND (rhs, 0)
6374 = instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6375 if (TREE_OPERAND (rhs, 0) == error_mark_node)
6376 return error_mark_node;
6377 TREE_OPERAND (rhs, 1)
6378 = instantiate_type (lhstype, TREE_OPERAND (rhs, 1), flags);
6379 if (TREE_OPERAND (rhs, 1) == error_mark_node)
6380 return error_mark_node;
6382 TREE_TYPE (rhs) = lhstype;
6387 if (PTRMEM_OK_P (rhs))
6388 flags |= tf_ptrmem_ok;
6390 return instantiate_type (lhstype, TREE_OPERAND (rhs, 0), flags);
6394 return error_mark_node;
6399 return error_mark_node;
6402 /* Return the name of the virtual function pointer field
6403 (as an IDENTIFIER_NODE) for the given TYPE. Note that
6404 this may have to look back through base types to find the
6405 ultimate field name. (For single inheritance, these could
6406 all be the same name. Who knows for multiple inheritance). */
6409 get_vfield_name (tree type)
6411 tree binfo, base_binfo;
6414 for (binfo = TYPE_BINFO (type);
6415 BINFO_N_BASE_BINFOS (binfo);
6418 base_binfo = BINFO_BASE_BINFO (binfo, 0);
6420 if (BINFO_VIRTUAL_P (base_binfo)
6421 || !TYPE_CONTAINS_VPTR_P (BINFO_TYPE (base_binfo)))
6425 type = BINFO_TYPE (binfo);
6426 buf = (char *) alloca (sizeof (VFIELD_NAME_FORMAT)
6427 + TYPE_NAME_LENGTH (type) + 2);
6428 sprintf (buf, VFIELD_NAME_FORMAT,
6429 IDENTIFIER_POINTER (constructor_name (type)));
6430 return get_identifier (buf);
6434 print_class_statistics (void)
6436 #ifdef GATHER_STATISTICS
6437 fprintf (stderr, "convert_harshness = %d\n", n_convert_harshness);
6438 fprintf (stderr, "compute_conversion_costs = %d\n", n_compute_conversion_costs);
6441 fprintf (stderr, "vtables = %d; vtable searches = %d\n",
6442 n_vtables, n_vtable_searches);
6443 fprintf (stderr, "vtable entries = %d; vtable elems = %d\n",
6444 n_vtable_entries, n_vtable_elems);
6449 /* Build a dummy reference to ourselves so Derived::Base (and A::A) works,
6450 according to [class]:
6451 The class-name is also inserted
6452 into the scope of the class itself. For purposes of access checking,
6453 the inserted class name is treated as if it were a public member name. */
6456 build_self_reference (void)
6458 tree name = constructor_name (current_class_type);
6459 tree value = build_lang_decl (TYPE_DECL, name, current_class_type);
6462 DECL_NONLOCAL (value) = 1;
6463 DECL_CONTEXT (value) = current_class_type;
6464 DECL_ARTIFICIAL (value) = 1;
6465 SET_DECL_SELF_REFERENCE_P (value);
6467 if (processing_template_decl)
6468 value = push_template_decl (value);
6470 saved_cas = current_access_specifier;
6471 current_access_specifier = access_public_node;
6472 finish_member_declaration (value);
6473 current_access_specifier = saved_cas;
6476 /* Returns 1 if TYPE contains only padding bytes. */
6479 is_empty_class (tree type)
6481 if (type == error_mark_node)
6484 if (! CLASS_TYPE_P (type))
6487 /* In G++ 3.2, whether or not a class was empty was determined by
6488 looking at its size. */
6489 if (abi_version_at_least (2))
6490 return CLASSTYPE_EMPTY_P (type);
6492 return integer_zerop (CLASSTYPE_SIZE (type));
6495 /* Returns true if TYPE contains an empty class. */
6498 contains_empty_class_p (tree type)
6500 if (is_empty_class (type))
6502 if (CLASS_TYPE_P (type))
6509 for (binfo = TYPE_BINFO (type), i = 0;
6510 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6511 if (contains_empty_class_p (BINFO_TYPE (base_binfo)))
6513 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6514 if (TREE_CODE (field) == FIELD_DECL
6515 && !DECL_ARTIFICIAL (field)
6516 && is_empty_class (TREE_TYPE (field)))
6519 else if (TREE_CODE (type) == ARRAY_TYPE)
6520 return contains_empty_class_p (TREE_TYPE (type));
6524 /* Returns true if TYPE contains no actual data, just various
6525 possible combinations of empty classes. */
6528 is_really_empty_class (tree type)
6530 if (is_empty_class (type))
6532 if (CLASS_TYPE_P (type))
6539 for (binfo = TYPE_BINFO (type), i = 0;
6540 BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
6541 if (!is_really_empty_class (BINFO_TYPE (base_binfo)))
6543 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
6544 if (TREE_CODE (field) == FIELD_DECL
6545 && !DECL_ARTIFICIAL (field)
6546 && !is_really_empty_class (TREE_TYPE (field)))
6550 else if (TREE_CODE (type) == ARRAY_TYPE)
6551 return is_really_empty_class (TREE_TYPE (type));
6555 /* Note that NAME was looked up while the current class was being
6556 defined and that the result of that lookup was DECL. */
6559 maybe_note_name_used_in_class (tree name, tree decl)
6561 splay_tree names_used;
6563 /* If we're not defining a class, there's nothing to do. */
6564 if (!(innermost_scope_kind() == sk_class
6565 && TYPE_BEING_DEFINED (current_class_type)))
6568 /* If there's already a binding for this NAME, then we don't have
6569 anything to worry about. */
6570 if (lookup_member (current_class_type, name,
6571 /*protect=*/0, /*want_type=*/false))
6574 if (!current_class_stack[current_class_depth - 1].names_used)
6575 current_class_stack[current_class_depth - 1].names_used
6576 = splay_tree_new (splay_tree_compare_pointers, 0, 0);
6577 names_used = current_class_stack[current_class_depth - 1].names_used;
6579 splay_tree_insert (names_used,
6580 (splay_tree_key) name,
6581 (splay_tree_value) decl);
6584 /* Note that NAME was declared (as DECL) in the current class. Check
6585 to see that the declaration is valid. */
6588 note_name_declared_in_class (tree name, tree decl)
6590 splay_tree names_used;
6593 /* Look to see if we ever used this name. */
6595 = current_class_stack[current_class_depth - 1].names_used;
6599 n = splay_tree_lookup (names_used, (splay_tree_key) name);
6602 /* [basic.scope.class]
6604 A name N used in a class S shall refer to the same declaration
6605 in its context and when re-evaluated in the completed scope of
6607 permerror (input_location, "declaration of %q#D", decl);
6608 permerror (input_location, "changes meaning of %qD from %q+#D",
6609 DECL_NAME (OVL_CURRENT (decl)), (tree) n->value);
6613 /* Returns the VAR_DECL for the complete vtable associated with BINFO.
6614 Secondary vtables are merged with primary vtables; this function
6615 will return the VAR_DECL for the primary vtable. */
6618 get_vtbl_decl_for_binfo (tree binfo)
6622 decl = BINFO_VTABLE (binfo);
6623 if (decl && TREE_CODE (decl) == POINTER_PLUS_EXPR)
6625 gcc_assert (TREE_CODE (TREE_OPERAND (decl, 0)) == ADDR_EXPR);
6626 decl = TREE_OPERAND (TREE_OPERAND (decl, 0), 0);
6629 gcc_assert (TREE_CODE (decl) == VAR_DECL);
6634 /* Returns the binfo for the primary base of BINFO. If the resulting
6635 BINFO is a virtual base, and it is inherited elsewhere in the
6636 hierarchy, then the returned binfo might not be the primary base of
6637 BINFO in the complete object. Check BINFO_PRIMARY_P or
6638 BINFO_LOST_PRIMARY_P to be sure. */
6641 get_primary_binfo (tree binfo)
6645 primary_base = CLASSTYPE_PRIMARY_BINFO (BINFO_TYPE (binfo));
6649 return copied_binfo (primary_base, binfo);
6652 /* If INDENTED_P is zero, indent to INDENT. Return nonzero. */
6655 maybe_indent_hierarchy (FILE * stream, int indent, int indented_p)
6658 fprintf (stream, "%*s", indent, "");
6662 /* Dump the offsets of all the bases rooted at BINFO to STREAM.
6663 INDENT should be zero when called from the top level; it is
6664 incremented recursively. IGO indicates the next expected BINFO in
6665 inheritance graph ordering. */
6668 dump_class_hierarchy_r (FILE *stream,
6678 indented = maybe_indent_hierarchy (stream, indent, 0);
6679 fprintf (stream, "%s (0x%lx) ",
6680 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER),
6681 (unsigned long) binfo);
6684 fprintf (stream, "alternative-path\n");
6687 igo = TREE_CHAIN (binfo);
6689 fprintf (stream, HOST_WIDE_INT_PRINT_DEC,
6690 tree_low_cst (BINFO_OFFSET (binfo), 0));
6691 if (is_empty_class (BINFO_TYPE (binfo)))
6692 fprintf (stream, " empty");
6693 else if (CLASSTYPE_NEARLY_EMPTY_P (BINFO_TYPE (binfo)))
6694 fprintf (stream, " nearly-empty");
6695 if (BINFO_VIRTUAL_P (binfo))
6696 fprintf (stream, " virtual");
6697 fprintf (stream, "\n");
6700 if (BINFO_PRIMARY_P (binfo))
6702 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6703 fprintf (stream, " primary-for %s (0x%lx)",
6704 type_as_string (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
6705 TFF_PLAIN_IDENTIFIER),
6706 (unsigned long)BINFO_INHERITANCE_CHAIN (binfo));
6708 if (BINFO_LOST_PRIMARY_P (binfo))
6710 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6711 fprintf (stream, " lost-primary");
6714 fprintf (stream, "\n");
6716 if (!(flags & TDF_SLIM))
6720 if (BINFO_SUBVTT_INDEX (binfo))
6722 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6723 fprintf (stream, " subvttidx=%s",
6724 expr_as_string (BINFO_SUBVTT_INDEX (binfo),
6725 TFF_PLAIN_IDENTIFIER));
6727 if (BINFO_VPTR_INDEX (binfo))
6729 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6730 fprintf (stream, " vptridx=%s",
6731 expr_as_string (BINFO_VPTR_INDEX (binfo),
6732 TFF_PLAIN_IDENTIFIER));
6734 if (BINFO_VPTR_FIELD (binfo))
6736 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6737 fprintf (stream, " vbaseoffset=%s",
6738 expr_as_string (BINFO_VPTR_FIELD (binfo),
6739 TFF_PLAIN_IDENTIFIER));
6741 if (BINFO_VTABLE (binfo))
6743 indented = maybe_indent_hierarchy (stream, indent + 3, indented);
6744 fprintf (stream, " vptr=%s",
6745 expr_as_string (BINFO_VTABLE (binfo),
6746 TFF_PLAIN_IDENTIFIER));
6750 fprintf (stream, "\n");
6753 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
6754 igo = dump_class_hierarchy_r (stream, flags, base_binfo, igo, indent + 2);
6759 /* Dump the BINFO hierarchy for T. */
6762 dump_class_hierarchy_1 (FILE *stream, int flags, tree t)
6764 fprintf (stream, "Class %s\n", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6765 fprintf (stream, " size=%lu align=%lu\n",
6766 (unsigned long)(tree_low_cst (TYPE_SIZE (t), 0) / BITS_PER_UNIT),
6767 (unsigned long)(TYPE_ALIGN (t) / BITS_PER_UNIT));
6768 fprintf (stream, " base size=%lu base align=%lu\n",
6769 (unsigned long)(tree_low_cst (TYPE_SIZE (CLASSTYPE_AS_BASE (t)), 0)
6771 (unsigned long)(TYPE_ALIGN (CLASSTYPE_AS_BASE (t))
6773 dump_class_hierarchy_r (stream, flags, TYPE_BINFO (t), TYPE_BINFO (t), 0);
6774 fprintf (stream, "\n");
6777 /* Debug interface to hierarchy dumping. */
6780 debug_class (tree t)
6782 dump_class_hierarchy_1 (stderr, TDF_SLIM, t);
6786 dump_class_hierarchy (tree t)
6789 FILE *stream = dump_begin (TDI_class, &flags);
6793 dump_class_hierarchy_1 (stream, flags, t);
6794 dump_end (TDI_class, stream);
6799 dump_array (FILE * stream, tree decl)
6802 unsigned HOST_WIDE_INT ix;
6804 tree size = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (decl)));
6806 elt = (tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (decl))), 0)
6808 fprintf (stream, "%s:", decl_as_string (decl, TFF_PLAIN_IDENTIFIER));
6809 fprintf (stream, " %s entries",
6810 expr_as_string (size_binop (PLUS_EXPR, size, size_one_node),
6811 TFF_PLAIN_IDENTIFIER));
6812 fprintf (stream, "\n");
6814 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
6816 fprintf (stream, "%-4ld %s\n", (long)(ix * elt),
6817 expr_as_string (value, TFF_PLAIN_IDENTIFIER));
6821 dump_vtable (tree t, tree binfo, tree vtable)
6824 FILE *stream = dump_begin (TDI_class, &flags);
6829 if (!(flags & TDF_SLIM))
6831 int ctor_vtbl_p = TYPE_BINFO (t) != binfo;
6833 fprintf (stream, "%s for %s",
6834 ctor_vtbl_p ? "Construction vtable" : "Vtable",
6835 type_as_string (BINFO_TYPE (binfo), TFF_PLAIN_IDENTIFIER));
6838 if (!BINFO_VIRTUAL_P (binfo))
6839 fprintf (stream, " (0x%lx instance)", (unsigned long)binfo);
6840 fprintf (stream, " in %s", type_as_string (t, TFF_PLAIN_IDENTIFIER));
6842 fprintf (stream, "\n");
6843 dump_array (stream, vtable);
6844 fprintf (stream, "\n");
6847 dump_end (TDI_class, stream);
6851 dump_vtt (tree t, tree vtt)
6854 FILE *stream = dump_begin (TDI_class, &flags);
6859 if (!(flags & TDF_SLIM))
6861 fprintf (stream, "VTT for %s\n",
6862 type_as_string (t, TFF_PLAIN_IDENTIFIER));
6863 dump_array (stream, vtt);
6864 fprintf (stream, "\n");
6867 dump_end (TDI_class, stream);
6870 /* Dump a function or thunk and its thunkees. */
6873 dump_thunk (FILE *stream, int indent, tree thunk)
6875 static const char spaces[] = " ";
6876 tree name = DECL_NAME (thunk);
6879 fprintf (stream, "%.*s%p %s %s", indent, spaces,
6881 !DECL_THUNK_P (thunk) ? "function"
6882 : DECL_THIS_THUNK_P (thunk) ? "this-thunk" : "covariant-thunk",
6883 name ? IDENTIFIER_POINTER (name) : "<unset>");
6884 if (DECL_THUNK_P (thunk))
6886 HOST_WIDE_INT fixed_adjust = THUNK_FIXED_OFFSET (thunk);
6887 tree virtual_adjust = THUNK_VIRTUAL_OFFSET (thunk);
6889 fprintf (stream, " fixed=" HOST_WIDE_INT_PRINT_DEC, fixed_adjust);
6890 if (!virtual_adjust)
6892 else if (DECL_THIS_THUNK_P (thunk))
6893 fprintf (stream, " vcall=" HOST_WIDE_INT_PRINT_DEC,
6894 tree_low_cst (virtual_adjust, 0));
6896 fprintf (stream, " vbase=" HOST_WIDE_INT_PRINT_DEC "(%s)",
6897 tree_low_cst (BINFO_VPTR_FIELD (virtual_adjust), 0),
6898 type_as_string (BINFO_TYPE (virtual_adjust), TFF_SCOPE));
6899 if (THUNK_ALIAS (thunk))
6900 fprintf (stream, " alias to %p", (void *)THUNK_ALIAS (thunk));
6902 fprintf (stream, "\n");
6903 for (thunks = DECL_THUNKS (thunk); thunks; thunks = TREE_CHAIN (thunks))
6904 dump_thunk (stream, indent + 2, thunks);
6907 /* Dump the thunks for FN. */
6910 debug_thunks (tree fn)
6912 dump_thunk (stderr, 0, fn);
6915 /* Virtual function table initialization. */
6917 /* Create all the necessary vtables for T and its base classes. */
6920 finish_vtbls (tree t)
6925 /* We lay out the primary and secondary vtables in one contiguous
6926 vtable. The primary vtable is first, followed by the non-virtual
6927 secondary vtables in inheritance graph order. */
6928 list = build_tree_list (BINFO_VTABLE (TYPE_BINFO (t)), NULL_TREE);
6929 accumulate_vtbl_inits (TYPE_BINFO (t), TYPE_BINFO (t),
6930 TYPE_BINFO (t), t, list);
6932 /* Then come the virtual bases, also in inheritance graph order. */
6933 for (vbase = TYPE_BINFO (t); vbase; vbase = TREE_CHAIN (vbase))
6935 if (!BINFO_VIRTUAL_P (vbase))
6937 accumulate_vtbl_inits (vbase, vbase, TYPE_BINFO (t), t, list);
6940 if (BINFO_VTABLE (TYPE_BINFO (t)))
6941 initialize_vtable (TYPE_BINFO (t), TREE_VALUE (list));
6944 /* Initialize the vtable for BINFO with the INITS. */
6947 initialize_vtable (tree binfo, tree inits)
6951 layout_vtable_decl (binfo, list_length (inits));
6952 decl = get_vtbl_decl_for_binfo (binfo);
6953 initialize_artificial_var (decl, inits);
6954 dump_vtable (BINFO_TYPE (binfo), binfo, decl);
6957 /* Build the VTT (virtual table table) for T.
6958 A class requires a VTT if it has virtual bases.
6961 1 - primary virtual pointer for complete object T
6962 2 - secondary VTTs for each direct non-virtual base of T which requires a
6964 3 - secondary virtual pointers for each direct or indirect base of T which
6965 has virtual bases or is reachable via a virtual path from T.
6966 4 - secondary VTTs for each direct or indirect virtual base of T.
6968 Secondary VTTs look like complete object VTTs without part 4. */
6978 /* Build up the initializers for the VTT. */
6980 index = size_zero_node;
6981 build_vtt_inits (TYPE_BINFO (t), t, &inits, &index);
6983 /* If we didn't need a VTT, we're done. */
6987 /* Figure out the type of the VTT. */
6988 type = build_index_type (size_int (list_length (inits) - 1));
6989 type = build_cplus_array_type (const_ptr_type_node, type);
6991 /* Now, build the VTT object itself. */
6992 vtt = build_vtable (t, mangle_vtt_for_type (t), type);
6993 initialize_artificial_var (vtt, inits);
6994 /* Add the VTT to the vtables list. */
6995 TREE_CHAIN (vtt) = TREE_CHAIN (CLASSTYPE_VTABLES (t));
6996 TREE_CHAIN (CLASSTYPE_VTABLES (t)) = vtt;
7001 /* When building a secondary VTT, BINFO_VTABLE is set to a TREE_LIST with
7002 PURPOSE the RTTI_BINFO, VALUE the real vtable pointer for this binfo,
7003 and CHAIN the vtable pointer for this binfo after construction is
7004 complete. VALUE can also be another BINFO, in which case we recurse. */
7007 binfo_ctor_vtable (tree binfo)
7013 vt = BINFO_VTABLE (binfo);
7014 if (TREE_CODE (vt) == TREE_LIST)
7015 vt = TREE_VALUE (vt);
7016 if (TREE_CODE (vt) == TREE_BINFO)
7025 /* Data for secondary VTT initialization. */
7026 typedef struct secondary_vptr_vtt_init_data_s
7028 /* Is this the primary VTT? */
7031 /* Current index into the VTT. */
7034 /* TREE_LIST of initializers built up. */
7037 /* The type being constructed by this secondary VTT. */
7038 tree type_being_constructed;
7039 } secondary_vptr_vtt_init_data;
7041 /* Recursively build the VTT-initializer for BINFO (which is in the
7042 hierarchy dominated by T). INITS points to the end of the initializer
7043 list to date. INDEX is the VTT index where the next element will be
7044 replaced. Iff BINFO is the binfo for T, this is the top level VTT (i.e.
7045 not a subvtt for some base of T). When that is so, we emit the sub-VTTs
7046 for virtual bases of T. When it is not so, we build the constructor
7047 vtables for the BINFO-in-T variant. */
7050 build_vtt_inits (tree binfo, tree t, tree *inits, tree *index)
7055 tree secondary_vptrs;
7056 secondary_vptr_vtt_init_data data;
7057 int top_level_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7059 /* We only need VTTs for subobjects with virtual bases. */
7060 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7063 /* We need to use a construction vtable if this is not the primary
7067 build_ctor_vtbl_group (binfo, t);
7069 /* Record the offset in the VTT where this sub-VTT can be found. */
7070 BINFO_SUBVTT_INDEX (binfo) = *index;
7073 /* Add the address of the primary vtable for the complete object. */
7074 init = binfo_ctor_vtable (binfo);
7075 *inits = build_tree_list (NULL_TREE, init);
7076 inits = &TREE_CHAIN (*inits);
7079 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7080 BINFO_VPTR_INDEX (binfo) = *index;
7082 *index = size_binop (PLUS_EXPR, *index, TYPE_SIZE_UNIT (ptr_type_node));
7084 /* Recursively add the secondary VTTs for non-virtual bases. */
7085 for (i = 0; BINFO_BASE_ITERATE (binfo, i, b); ++i)
7086 if (!BINFO_VIRTUAL_P (b))
7087 inits = build_vtt_inits (b, t, inits, index);
7089 /* Add secondary virtual pointers for all subobjects of BINFO with
7090 either virtual bases or reachable along a virtual path, except
7091 subobjects that are non-virtual primary bases. */
7092 data.top_level_p = top_level_p;
7093 data.index = *index;
7095 data.type_being_constructed = BINFO_TYPE (binfo);
7097 dfs_walk_once (binfo, dfs_build_secondary_vptr_vtt_inits, NULL, &data);
7099 *index = data.index;
7101 /* The secondary vptrs come back in reverse order. After we reverse
7102 them, and add the INITS, the last init will be the first element
7104 secondary_vptrs = data.inits;
7105 if (secondary_vptrs)
7107 *inits = nreverse (secondary_vptrs);
7108 inits = &TREE_CHAIN (secondary_vptrs);
7109 gcc_assert (*inits == NULL_TREE);
7113 /* Add the secondary VTTs for virtual bases in inheritance graph
7115 for (b = TYPE_BINFO (BINFO_TYPE (binfo)); b; b = TREE_CHAIN (b))
7117 if (!BINFO_VIRTUAL_P (b))
7120 inits = build_vtt_inits (b, t, inits, index);
7123 /* Remove the ctor vtables we created. */
7124 dfs_walk_all (binfo, dfs_fixup_binfo_vtbls, NULL, binfo);
7129 /* Called from build_vtt_inits via dfs_walk. BINFO is the binfo for the base
7130 in most derived. DATA is a SECONDARY_VPTR_VTT_INIT_DATA structure. */
7133 dfs_build_secondary_vptr_vtt_inits (tree binfo, void *data_)
7135 secondary_vptr_vtt_init_data *data = (secondary_vptr_vtt_init_data *)data_;
7137 /* We don't care about bases that don't have vtables. */
7138 if (!TYPE_VFIELD (BINFO_TYPE (binfo)))
7139 return dfs_skip_bases;
7141 /* We're only interested in proper subobjects of the type being
7143 if (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), data->type_being_constructed))
7146 /* We're only interested in bases with virtual bases or reachable
7147 via a virtual path from the type being constructed. */
7148 if (!(CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7149 || binfo_via_virtual (binfo, data->type_being_constructed)))
7150 return dfs_skip_bases;
7152 /* We're not interested in non-virtual primary bases. */
7153 if (!BINFO_VIRTUAL_P (binfo) && BINFO_PRIMARY_P (binfo))
7156 /* Record the index where this secondary vptr can be found. */
7157 if (data->top_level_p)
7159 gcc_assert (!BINFO_VPTR_INDEX (binfo));
7160 BINFO_VPTR_INDEX (binfo) = data->index;
7162 if (BINFO_VIRTUAL_P (binfo))
7164 /* It's a primary virtual base, and this is not a
7165 construction vtable. Find the base this is primary of in
7166 the inheritance graph, and use that base's vtable
7168 while (BINFO_PRIMARY_P (binfo))
7169 binfo = BINFO_INHERITANCE_CHAIN (binfo);
7173 /* Add the initializer for the secondary vptr itself. */
7174 data->inits = tree_cons (NULL_TREE, binfo_ctor_vtable (binfo), data->inits);
7176 /* Advance the vtt index. */
7177 data->index = size_binop (PLUS_EXPR, data->index,
7178 TYPE_SIZE_UNIT (ptr_type_node));
7183 /* Called from build_vtt_inits via dfs_walk. After building
7184 constructor vtables and generating the sub-vtt from them, we need
7185 to restore the BINFO_VTABLES that were scribbled on. DATA is the
7186 binfo of the base whose sub vtt was generated. */
7189 dfs_fixup_binfo_vtbls (tree binfo, void* data)
7191 tree vtable = BINFO_VTABLE (binfo);
7193 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7194 /* If this class has no vtable, none of its bases do. */
7195 return dfs_skip_bases;
7198 /* This might be a primary base, so have no vtable in this
7202 /* If we scribbled the construction vtable vptr into BINFO, clear it
7204 if (TREE_CODE (vtable) == TREE_LIST
7205 && (TREE_PURPOSE (vtable) == (tree) data))
7206 BINFO_VTABLE (binfo) = TREE_CHAIN (vtable);
7211 /* Build the construction vtable group for BINFO which is in the
7212 hierarchy dominated by T. */
7215 build_ctor_vtbl_group (tree binfo, tree t)
7224 /* See if we've already created this construction vtable group. */
7225 id = mangle_ctor_vtbl_for_type (t, binfo);
7226 if (IDENTIFIER_GLOBAL_VALUE (id))
7229 gcc_assert (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t));
7230 /* Build a version of VTBL (with the wrong type) for use in
7231 constructing the addresses of secondary vtables in the
7232 construction vtable group. */
7233 vtbl = build_vtable (t, id, ptr_type_node);
7234 DECL_CONSTRUCTION_VTABLE_P (vtbl) = 1;
7235 list = build_tree_list (vtbl, NULL_TREE);
7236 accumulate_vtbl_inits (binfo, TYPE_BINFO (TREE_TYPE (binfo)),
7239 /* Add the vtables for each of our virtual bases using the vbase in T
7241 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7243 vbase = TREE_CHAIN (vbase))
7247 if (!BINFO_VIRTUAL_P (vbase))
7249 b = copied_binfo (vbase, binfo);
7251 accumulate_vtbl_inits (b, vbase, binfo, t, list);
7253 inits = TREE_VALUE (list);
7255 /* Figure out the type of the construction vtable. */
7256 type = build_index_type (size_int (list_length (inits) - 1));
7257 type = build_cplus_array_type (vtable_entry_type, type);
7259 TREE_TYPE (vtbl) = type;
7260 DECL_SIZE (vtbl) = DECL_SIZE_UNIT (vtbl) = NULL_TREE;
7261 layout_decl (vtbl, 0);
7263 /* Initialize the construction vtable. */
7264 CLASSTYPE_VTABLES (t) = chainon (CLASSTYPE_VTABLES (t), vtbl);
7265 initialize_artificial_var (vtbl, inits);
7266 dump_vtable (t, binfo, vtbl);
7269 /* Add the vtbl initializers for BINFO (and its bases other than
7270 non-virtual primaries) to the list of INITS. BINFO is in the
7271 hierarchy dominated by T. RTTI_BINFO is the binfo within T of
7272 the constructor the vtbl inits should be accumulated for. (If this
7273 is the complete object vtbl then RTTI_BINFO will be TYPE_BINFO (T).)
7274 ORIG_BINFO is the binfo for this object within BINFO_TYPE (RTTI_BINFO).
7275 BINFO is the active base equivalent of ORIG_BINFO in the inheritance
7276 graph of T. Both BINFO and ORIG_BINFO will have the same BINFO_TYPE,
7277 but are not necessarily the same in terms of layout. */
7280 accumulate_vtbl_inits (tree binfo,
7288 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7290 gcc_assert (SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), BINFO_TYPE (orig_binfo)));
7292 /* If it doesn't have a vptr, we don't do anything. */
7293 if (!TYPE_CONTAINS_VPTR_P (BINFO_TYPE (binfo)))
7296 /* If we're building a construction vtable, we're not interested in
7297 subobjects that don't require construction vtables. */
7299 && !CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo))
7300 && !binfo_via_virtual (orig_binfo, BINFO_TYPE (rtti_binfo)))
7303 /* Build the initializers for the BINFO-in-T vtable. */
7305 = chainon (TREE_VALUE (inits),
7306 dfs_accumulate_vtbl_inits (binfo, orig_binfo,
7307 rtti_binfo, t, inits));
7309 /* Walk the BINFO and its bases. We walk in preorder so that as we
7310 initialize each vtable we can figure out at what offset the
7311 secondary vtable lies from the primary vtable. We can't use
7312 dfs_walk here because we need to iterate through bases of BINFO
7313 and RTTI_BINFO simultaneously. */
7314 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7316 /* Skip virtual bases. */
7317 if (BINFO_VIRTUAL_P (base_binfo))
7319 accumulate_vtbl_inits (base_binfo,
7320 BINFO_BASE_BINFO (orig_binfo, i),
7326 /* Called from accumulate_vtbl_inits. Returns the initializers for
7327 the BINFO vtable. */
7330 dfs_accumulate_vtbl_inits (tree binfo,
7336 tree inits = NULL_TREE;
7337 tree vtbl = NULL_TREE;
7338 int ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7341 && BINFO_VIRTUAL_P (orig_binfo) && BINFO_PRIMARY_P (orig_binfo))
7343 /* In the hierarchy of BINFO_TYPE (RTTI_BINFO), this is a
7344 primary virtual base. If it is not the same primary in
7345 the hierarchy of T, we'll need to generate a ctor vtable
7346 for it, to place at its location in T. If it is the same
7347 primary, we still need a VTT entry for the vtable, but it
7348 should point to the ctor vtable for the base it is a
7349 primary for within the sub-hierarchy of RTTI_BINFO.
7351 There are three possible cases:
7353 1) We are in the same place.
7354 2) We are a primary base within a lost primary virtual base of
7356 3) We are primary to something not a base of RTTI_BINFO. */
7359 tree last = NULL_TREE;
7361 /* First, look through the bases we are primary to for RTTI_BINFO
7362 or a virtual base. */
7364 while (BINFO_PRIMARY_P (b))
7366 b = BINFO_INHERITANCE_CHAIN (b);
7368 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7371 /* If we run out of primary links, keep looking down our
7372 inheritance chain; we might be an indirect primary. */
7373 for (b = last; b; b = BINFO_INHERITANCE_CHAIN (b))
7374 if (BINFO_VIRTUAL_P (b) || b == rtti_binfo)
7378 /* If we found RTTI_BINFO, this is case 1. If we found a virtual
7379 base B and it is a base of RTTI_BINFO, this is case 2. In
7380 either case, we share our vtable with LAST, i.e. the
7381 derived-most base within B of which we are a primary. */
7383 || (b && binfo_for_vbase (BINFO_TYPE (b), BINFO_TYPE (rtti_binfo))))
7384 /* Just set our BINFO_VTABLE to point to LAST, as we may not have
7385 set LAST's BINFO_VTABLE yet. We'll extract the actual vptr in
7386 binfo_ctor_vtable after everything's been set up. */
7389 /* Otherwise, this is case 3 and we get our own. */
7391 else if (!BINFO_NEW_VTABLE_MARKED (orig_binfo))
7399 /* Compute the initializer for this vtable. */
7400 inits = build_vtbl_initializer (binfo, orig_binfo, t, rtti_binfo,
7403 /* Figure out the position to which the VPTR should point. */
7404 vtbl = TREE_PURPOSE (l);
7405 vtbl = build1 (ADDR_EXPR, vtbl_ptr_type_node, vtbl);
7406 index = size_binop (PLUS_EXPR,
7407 size_int (non_fn_entries),
7408 size_int (list_length (TREE_VALUE (l))));
7409 index = size_binop (MULT_EXPR,
7410 TYPE_SIZE_UNIT (vtable_entry_type),
7412 vtbl = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtbl), vtbl, index);
7416 /* For a construction vtable, we can't overwrite BINFO_VTABLE.
7417 So, we make a TREE_LIST. Later, dfs_fixup_binfo_vtbls will
7418 straighten this out. */
7419 BINFO_VTABLE (binfo) = tree_cons (rtti_binfo, vtbl, BINFO_VTABLE (binfo));
7420 else if (BINFO_PRIMARY_P (binfo) && BINFO_VIRTUAL_P (binfo))
7423 /* For an ordinary vtable, set BINFO_VTABLE. */
7424 BINFO_VTABLE (binfo) = vtbl;
7429 static GTY(()) tree abort_fndecl_addr;
7431 /* Construct the initializer for BINFO's virtual function table. BINFO
7432 is part of the hierarchy dominated by T. If we're building a
7433 construction vtable, the ORIG_BINFO is the binfo we should use to
7434 find the actual function pointers to put in the vtable - but they
7435 can be overridden on the path to most-derived in the graph that
7436 ORIG_BINFO belongs. Otherwise,
7437 ORIG_BINFO should be the same as BINFO. The RTTI_BINFO is the
7438 BINFO that should be indicated by the RTTI information in the
7439 vtable; it will be a base class of T, rather than T itself, if we
7440 are building a construction vtable.
7442 The value returned is a TREE_LIST suitable for wrapping in a
7443 CONSTRUCTOR to use as the DECL_INITIAL for a vtable. If
7444 NON_FN_ENTRIES_P is not NULL, *NON_FN_ENTRIES_P is set to the
7445 number of non-function entries in the vtable.
7447 It might seem that this function should never be called with a
7448 BINFO for which BINFO_PRIMARY_P holds, the vtable for such a
7449 base is always subsumed by a derived class vtable. However, when
7450 we are building construction vtables, we do build vtables for
7451 primary bases; we need these while the primary base is being
7455 build_vtbl_initializer (tree binfo,
7459 int* non_fn_entries_p)
7466 VEC(tree,gc) *vbases;
7468 /* Initialize VID. */
7469 memset (&vid, 0, sizeof (vid));
7472 vid.rtti_binfo = rtti_binfo;
7473 vid.last_init = &vid.inits;
7474 vid.primary_vtbl_p = SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), t);
7475 vid.ctor_vtbl_p = !SAME_BINFO_TYPE_P (BINFO_TYPE (rtti_binfo), t);
7476 vid.generate_vcall_entries = true;
7477 /* The first vbase or vcall offset is at index -3 in the vtable. */
7478 vid.index = ssize_int(-3 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
7480 /* Add entries to the vtable for RTTI. */
7481 build_rtti_vtbl_entries (binfo, &vid);
7483 /* Create an array for keeping track of the functions we've
7484 processed. When we see multiple functions with the same
7485 signature, we share the vcall offsets. */
7486 vid.fns = VEC_alloc (tree, gc, 32);
7487 /* Add the vcall and vbase offset entries. */
7488 build_vcall_and_vbase_vtbl_entries (binfo, &vid);
7490 /* Clear BINFO_VTABLE_PATH_MARKED; it's set by
7491 build_vbase_offset_vtbl_entries. */
7492 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
7493 VEC_iterate (tree, vbases, ix, vbinfo); ix++)
7494 BINFO_VTABLE_PATH_MARKED (vbinfo) = 0;
7496 /* If the target requires padding between data entries, add that now. */
7497 if (TARGET_VTABLE_DATA_ENTRY_DISTANCE > 1)
7501 for (prev = &vid.inits; (cur = *prev); prev = &TREE_CHAIN (cur))
7506 for (i = 1; i < TARGET_VTABLE_DATA_ENTRY_DISTANCE; ++i)
7507 add = tree_cons (NULL_TREE,
7508 build1 (NOP_EXPR, vtable_entry_type,
7515 if (non_fn_entries_p)
7516 *non_fn_entries_p = list_length (vid.inits);
7518 /* Go through all the ordinary virtual functions, building up
7520 vfun_inits = NULL_TREE;
7521 for (v = BINFO_VIRTUALS (orig_binfo); v; v = TREE_CHAIN (v))
7525 tree fn, fn_original;
7526 tree init = NULL_TREE;
7530 if (DECL_THUNK_P (fn))
7532 if (!DECL_NAME (fn))
7534 if (THUNK_ALIAS (fn))
7536 fn = THUNK_ALIAS (fn);
7539 fn_original = THUNK_TARGET (fn);
7542 /* If the only definition of this function signature along our
7543 primary base chain is from a lost primary, this vtable slot will
7544 never be used, so just zero it out. This is important to avoid
7545 requiring extra thunks which cannot be generated with the function.
7547 We first check this in update_vtable_entry_for_fn, so we handle
7548 restored primary bases properly; we also need to do it here so we
7549 zero out unused slots in ctor vtables, rather than filling them
7550 with erroneous values (though harmless, apart from relocation
7552 for (b = binfo; ; b = get_primary_binfo (b))
7554 /* We found a defn before a lost primary; go ahead as normal. */
7555 if (look_for_overrides_here (BINFO_TYPE (b), fn_original))
7558 /* The nearest definition is from a lost primary; clear the
7560 if (BINFO_LOST_PRIMARY_P (b))
7562 init = size_zero_node;
7569 /* Pull the offset for `this', and the function to call, out of
7571 delta = BV_DELTA (v);
7572 vcall_index = BV_VCALL_INDEX (v);
7574 gcc_assert (TREE_CODE (delta) == INTEGER_CST);
7575 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7577 /* You can't call an abstract virtual function; it's abstract.
7578 So, we replace these functions with __pure_virtual. */
7579 if (DECL_PURE_VIRTUAL_P (fn_original))
7582 if (abort_fndecl_addr == NULL)
7583 abort_fndecl_addr = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7584 init = abort_fndecl_addr;
7588 if (!integer_zerop (delta) || vcall_index)
7590 fn = make_thunk (fn, /*this_adjusting=*/1, delta, vcall_index);
7591 if (!DECL_NAME (fn))
7594 /* Take the address of the function, considering it to be of an
7595 appropriate generic type. */
7596 init = build1 (ADDR_EXPR, vfunc_ptr_type_node, fn);
7600 /* And add it to the chain of initializers. */
7601 if (TARGET_VTABLE_USES_DESCRIPTORS)
7604 if (init == size_zero_node)
7605 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7606 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7608 for (i = 0; i < TARGET_VTABLE_USES_DESCRIPTORS; ++i)
7610 tree fdesc = build2 (FDESC_EXPR, vfunc_ptr_type_node,
7611 TREE_OPERAND (init, 0),
7612 build_int_cst (NULL_TREE, i));
7613 TREE_CONSTANT (fdesc) = 1;
7615 vfun_inits = tree_cons (NULL_TREE, fdesc, vfun_inits);
7619 vfun_inits = tree_cons (NULL_TREE, init, vfun_inits);
7622 /* The initializers for virtual functions were built up in reverse
7623 order; straighten them out now. */
7624 vfun_inits = nreverse (vfun_inits);
7626 /* The negative offset initializers are also in reverse order. */
7627 vid.inits = nreverse (vid.inits);
7629 /* Chain the two together. */
7630 return chainon (vid.inits, vfun_inits);
7633 /* Adds to vid->inits the initializers for the vbase and vcall
7634 offsets in BINFO, which is in the hierarchy dominated by T. */
7637 build_vcall_and_vbase_vtbl_entries (tree binfo, vtbl_init_data* vid)
7641 /* If this is a derived class, we must first create entries
7642 corresponding to the primary base class. */
7643 b = get_primary_binfo (binfo);
7645 build_vcall_and_vbase_vtbl_entries (b, vid);
7647 /* Add the vbase entries for this base. */
7648 build_vbase_offset_vtbl_entries (binfo, vid);
7649 /* Add the vcall entries for this base. */
7650 build_vcall_offset_vtbl_entries (binfo, vid);
7653 /* Returns the initializers for the vbase offset entries in the vtable
7654 for BINFO (which is part of the class hierarchy dominated by T), in
7655 reverse order. VBASE_OFFSET_INDEX gives the vtable index
7656 where the next vbase offset will go. */
7659 build_vbase_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7663 tree non_primary_binfo;
7665 /* If there are no virtual baseclasses, then there is nothing to
7667 if (!CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)))
7672 /* We might be a primary base class. Go up the inheritance hierarchy
7673 until we find the most derived class of which we are a primary base:
7674 it is the offset of that which we need to use. */
7675 non_primary_binfo = binfo;
7676 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7680 /* If we have reached a virtual base, then it must be a primary
7681 base (possibly multi-level) of vid->binfo, or we wouldn't
7682 have called build_vcall_and_vbase_vtbl_entries for it. But it
7683 might be a lost primary, so just skip down to vid->binfo. */
7684 if (BINFO_VIRTUAL_P (non_primary_binfo))
7686 non_primary_binfo = vid->binfo;
7690 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7691 if (get_primary_binfo (b) != non_primary_binfo)
7693 non_primary_binfo = b;
7696 /* Go through the virtual bases, adding the offsets. */
7697 for (vbase = TYPE_BINFO (BINFO_TYPE (binfo));
7699 vbase = TREE_CHAIN (vbase))
7704 if (!BINFO_VIRTUAL_P (vbase))
7707 /* Find the instance of this virtual base in the complete
7709 b = copied_binfo (vbase, binfo);
7711 /* If we've already got an offset for this virtual base, we
7712 don't need another one. */
7713 if (BINFO_VTABLE_PATH_MARKED (b))
7715 BINFO_VTABLE_PATH_MARKED (b) = 1;
7717 /* Figure out where we can find this vbase offset. */
7718 delta = size_binop (MULT_EXPR,
7721 TYPE_SIZE_UNIT (vtable_entry_type)));
7722 if (vid->primary_vtbl_p)
7723 BINFO_VPTR_FIELD (b) = delta;
7725 if (binfo != TYPE_BINFO (t))
7726 /* The vbase offset had better be the same. */
7727 gcc_assert (tree_int_cst_equal (delta, BINFO_VPTR_FIELD (vbase)));
7729 /* The next vbase will come at a more negative offset. */
7730 vid->index = size_binop (MINUS_EXPR, vid->index,
7731 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7733 /* The initializer is the delta from BINFO to this virtual base.
7734 The vbase offsets go in reverse inheritance-graph order, and
7735 we are walking in inheritance graph order so these end up in
7737 delta = size_diffop (BINFO_OFFSET (b), BINFO_OFFSET (non_primary_binfo));
7740 = build_tree_list (NULL_TREE,
7741 fold_build1 (NOP_EXPR,
7744 vid->last_init = &TREE_CHAIN (*vid->last_init);
7748 /* Adds the initializers for the vcall offset entries in the vtable
7749 for BINFO (which is part of the class hierarchy dominated by VID->DERIVED)
7753 build_vcall_offset_vtbl_entries (tree binfo, vtbl_init_data* vid)
7755 /* We only need these entries if this base is a virtual base. We
7756 compute the indices -- but do not add to the vtable -- when
7757 building the main vtable for a class. */
7758 if (binfo == TYPE_BINFO (vid->derived)
7759 || (BINFO_VIRTUAL_P (binfo)
7760 /* If BINFO is RTTI_BINFO, then (since BINFO does not
7761 correspond to VID->DERIVED), we are building a primary
7762 construction virtual table. Since this is a primary
7763 virtual table, we do not need the vcall offsets for
7765 && binfo != vid->rtti_binfo))
7767 /* We need a vcall offset for each of the virtual functions in this
7768 vtable. For example:
7770 class A { virtual void f (); };
7771 class B1 : virtual public A { virtual void f (); };
7772 class B2 : virtual public A { virtual void f (); };
7773 class C: public B1, public B2 { virtual void f (); };
7775 A C object has a primary base of B1, which has a primary base of A. A
7776 C also has a secondary base of B2, which no longer has a primary base
7777 of A. So the B2-in-C construction vtable needs a secondary vtable for
7778 A, which will adjust the A* to a B2* to call f. We have no way of
7779 knowing what (or even whether) this offset will be when we define B2,
7780 so we store this "vcall offset" in the A sub-vtable and look it up in
7781 a "virtual thunk" for B2::f.
7783 We need entries for all the functions in our primary vtable and
7784 in our non-virtual bases' secondary vtables. */
7786 /* If we are just computing the vcall indices -- but do not need
7787 the actual entries -- not that. */
7788 if (!BINFO_VIRTUAL_P (binfo))
7789 vid->generate_vcall_entries = false;
7790 /* Now, walk through the non-virtual bases, adding vcall offsets. */
7791 add_vcall_offset_vtbl_entries_r (binfo, vid);
7795 /* Build vcall offsets, starting with those for BINFO. */
7798 add_vcall_offset_vtbl_entries_r (tree binfo, vtbl_init_data* vid)
7804 /* Don't walk into virtual bases -- except, of course, for the
7805 virtual base for which we are building vcall offsets. Any
7806 primary virtual base will have already had its offsets generated
7807 through the recursion in build_vcall_and_vbase_vtbl_entries. */
7808 if (BINFO_VIRTUAL_P (binfo) && vid->vbase != binfo)
7811 /* If BINFO has a primary base, process it first. */
7812 primary_binfo = get_primary_binfo (binfo);
7814 add_vcall_offset_vtbl_entries_r (primary_binfo, vid);
7816 /* Add BINFO itself to the list. */
7817 add_vcall_offset_vtbl_entries_1 (binfo, vid);
7819 /* Scan the non-primary bases of BINFO. */
7820 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); ++i)
7821 if (base_binfo != primary_binfo)
7822 add_vcall_offset_vtbl_entries_r (base_binfo, vid);
7825 /* Called from build_vcall_offset_vtbl_entries_r. */
7828 add_vcall_offset_vtbl_entries_1 (tree binfo, vtbl_init_data* vid)
7830 /* Make entries for the rest of the virtuals. */
7831 if (abi_version_at_least (2))
7835 /* The ABI requires that the methods be processed in declaration
7836 order. G++ 3.2 used the order in the vtable. */
7837 for (orig_fn = TYPE_METHODS (BINFO_TYPE (binfo));
7839 orig_fn = TREE_CHAIN (orig_fn))
7840 if (DECL_VINDEX (orig_fn))
7841 add_vcall_offset (orig_fn, binfo, vid);
7845 tree derived_virtuals;
7848 /* If BINFO is a primary base, the most derived class which has
7849 BINFO as a primary base; otherwise, just BINFO. */
7850 tree non_primary_binfo;
7852 /* We might be a primary base class. Go up the inheritance hierarchy
7853 until we find the most derived class of which we are a primary base:
7854 it is the BINFO_VIRTUALS there that we need to consider. */
7855 non_primary_binfo = binfo;
7856 while (BINFO_INHERITANCE_CHAIN (non_primary_binfo))
7860 /* If we have reached a virtual base, then it must be vid->vbase,
7861 because we ignore other virtual bases in
7862 add_vcall_offset_vtbl_entries_r. In turn, it must be a primary
7863 base (possibly multi-level) of vid->binfo, or we wouldn't
7864 have called build_vcall_and_vbase_vtbl_entries for it. But it
7865 might be a lost primary, so just skip down to vid->binfo. */
7866 if (BINFO_VIRTUAL_P (non_primary_binfo))
7868 gcc_assert (non_primary_binfo == vid->vbase);
7869 non_primary_binfo = vid->binfo;
7873 b = BINFO_INHERITANCE_CHAIN (non_primary_binfo);
7874 if (get_primary_binfo (b) != non_primary_binfo)
7876 non_primary_binfo = b;
7879 if (vid->ctor_vtbl_p)
7880 /* For a ctor vtable we need the equivalent binfo within the hierarchy
7881 where rtti_binfo is the most derived type. */
7883 = original_binfo (non_primary_binfo, vid->rtti_binfo);
7885 for (base_virtuals = BINFO_VIRTUALS (binfo),
7886 derived_virtuals = BINFO_VIRTUALS (non_primary_binfo),
7887 orig_virtuals = BINFO_VIRTUALS (TYPE_BINFO (BINFO_TYPE (binfo)));
7889 base_virtuals = TREE_CHAIN (base_virtuals),
7890 derived_virtuals = TREE_CHAIN (derived_virtuals),
7891 orig_virtuals = TREE_CHAIN (orig_virtuals))
7895 /* Find the declaration that originally caused this function to
7896 be present in BINFO_TYPE (binfo). */
7897 orig_fn = BV_FN (orig_virtuals);
7899 /* When processing BINFO, we only want to generate vcall slots for
7900 function slots introduced in BINFO. So don't try to generate
7901 one if the function isn't even defined in BINFO. */
7902 if (!SAME_BINFO_TYPE_P (BINFO_TYPE (binfo), DECL_CONTEXT (orig_fn)))
7905 add_vcall_offset (orig_fn, binfo, vid);
7910 /* Add a vcall offset entry for ORIG_FN to the vtable. */
7913 add_vcall_offset (tree orig_fn, tree binfo, vtbl_init_data *vid)
7919 /* If there is already an entry for a function with the same
7920 signature as FN, then we do not need a second vcall offset.
7921 Check the list of functions already present in the derived
7923 for (i = 0; VEC_iterate (tree, vid->fns, i, derived_entry); ++i)
7925 if (same_signature_p (derived_entry, orig_fn)
7926 /* We only use one vcall offset for virtual destructors,
7927 even though there are two virtual table entries. */
7928 || (DECL_DESTRUCTOR_P (derived_entry)
7929 && DECL_DESTRUCTOR_P (orig_fn)))
7933 /* If we are building these vcall offsets as part of building
7934 the vtable for the most derived class, remember the vcall
7936 if (vid->binfo == TYPE_BINFO (vid->derived))
7938 tree_pair_p elt = VEC_safe_push (tree_pair_s, gc,
7939 CLASSTYPE_VCALL_INDICES (vid->derived),
7941 elt->purpose = orig_fn;
7942 elt->value = vid->index;
7945 /* The next vcall offset will be found at a more negative
7947 vid->index = size_binop (MINUS_EXPR, vid->index,
7948 ssize_int (TARGET_VTABLE_DATA_ENTRY_DISTANCE));
7950 /* Keep track of this function. */
7951 VEC_safe_push (tree, gc, vid->fns, orig_fn);
7953 if (vid->generate_vcall_entries)
7958 /* Find the overriding function. */
7959 fn = find_final_overrider (vid->rtti_binfo, binfo, orig_fn);
7960 if (fn == error_mark_node)
7961 vcall_offset = build1 (NOP_EXPR, vtable_entry_type,
7965 base = TREE_VALUE (fn);
7967 /* The vbase we're working on is a primary base of
7968 vid->binfo. But it might be a lost primary, so its
7969 BINFO_OFFSET might be wrong, so we just use the
7970 BINFO_OFFSET from vid->binfo. */
7971 vcall_offset = size_diffop (BINFO_OFFSET (base),
7972 BINFO_OFFSET (vid->binfo));
7973 vcall_offset = fold_build1 (NOP_EXPR, vtable_entry_type,
7976 /* Add the initializer to the vtable. */
7977 *vid->last_init = build_tree_list (NULL_TREE, vcall_offset);
7978 vid->last_init = &TREE_CHAIN (*vid->last_init);
7982 /* Return vtbl initializers for the RTTI entries corresponding to the
7983 BINFO's vtable. The RTTI entries should indicate the object given
7984 by VID->rtti_binfo. */
7987 build_rtti_vtbl_entries (tree binfo, vtbl_init_data* vid)
7996 basetype = BINFO_TYPE (binfo);
7997 t = BINFO_TYPE (vid->rtti_binfo);
7999 /* To find the complete object, we will first convert to our most
8000 primary base, and then add the offset in the vtbl to that value. */
8002 while (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (b))
8003 && !BINFO_LOST_PRIMARY_P (b))
8007 primary_base = get_primary_binfo (b);
8008 gcc_assert (BINFO_PRIMARY_P (primary_base)
8009 && BINFO_INHERITANCE_CHAIN (primary_base) == b);
8012 offset = size_diffop (BINFO_OFFSET (vid->rtti_binfo), BINFO_OFFSET (b));
8014 /* The second entry is the address of the typeinfo object. */
8016 decl = build_address (get_tinfo_decl (t));
8018 decl = integer_zero_node;
8020 /* Convert the declaration to a type that can be stored in the
8022 init = build_nop (vfunc_ptr_type_node, decl);
8023 *vid->last_init = build_tree_list (NULL_TREE, init);
8024 vid->last_init = &TREE_CHAIN (*vid->last_init);
8026 /* Add the offset-to-top entry. It comes earlier in the vtable than
8027 the typeinfo entry. Convert the offset to look like a
8028 function pointer, so that we can put it in the vtable. */
8029 init = build_nop (vfunc_ptr_type_node, offset);
8030 *vid->last_init = build_tree_list (NULL_TREE, init);
8031 vid->last_init = &TREE_CHAIN (*vid->last_init);
8034 /* Fold a OBJ_TYPE_REF expression to the address of a function.
8035 KNOWN_TYPE carries the true type of OBJ_TYPE_REF_OBJECT(REF). */
8038 cp_fold_obj_type_ref (tree ref, tree known_type)
8040 HOST_WIDE_INT index = tree_low_cst (OBJ_TYPE_REF_TOKEN (ref), 1);
8041 HOST_WIDE_INT i = 0;
8042 tree v = BINFO_VIRTUALS (TYPE_BINFO (known_type));
8047 i += (TARGET_VTABLE_USES_DESCRIPTORS
8048 ? TARGET_VTABLE_USES_DESCRIPTORS : 1);
8054 #ifdef ENABLE_CHECKING
8055 gcc_assert (tree_int_cst_equal (OBJ_TYPE_REF_TOKEN (ref),
8056 DECL_VINDEX (fndecl)));
8059 cgraph_node (fndecl)->local.vtable_method = true;
8061 return build_address (fndecl);
8064 #include "gt-cp-class.h"