PR c++/14369
[official-gcc.git] / gcc / cp / rtti.c
blobfb611a76f9109a4e33bd1e8da6dd574d90e26908
1 /* RunTime Type Identification
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004
3 Free Software Foundation, Inc.
4 Mostly written by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2, or (at your option)
11 any later version.
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to
20 the Free Software Foundation, 59 Temple Place - Suite 330,
21 Boston, MA 02111-1307, USA. */
24 #include "config.h"
25 #include "system.h"
26 #include "coretypes.h"
27 #include "tm.h"
28 #include "tree.h"
29 #include "cp-tree.h"
30 #include "flags.h"
31 #include "output.h"
32 #include "assert.h"
33 #include "toplev.h"
34 #include "convert.h"
36 /* C++ returns type information to the user in struct type_info
37 objects. We also use type information to implement dynamic_cast and
38 exception handlers. Type information for a particular type is
39 indicated with an ABI defined structure derived from type_info.
40 This would all be very straight forward, but for the fact that the
41 runtime library provides the definitions of the type_info structure
42 and the ABI defined derived classes. We cannot build declarations
43 of them directly in the compiler, but we need to layout objects of
44 their type. Somewhere we have to lie.
46 We define layout compatible POD-structs with compiler-defined names
47 and generate the appropriate initializations for them (complete
48 with explicit mention of their vtable). When we have to provide a
49 type_info to the user we reinterpret_cast the internal compiler
50 type to type_info. A well formed program can only explicitly refer
51 to the type_infos of complete types (& cv void). However, we chain
52 pointer type_infos to the pointed-to-type, and that can be
53 incomplete. We only need the addresses of such incomplete
54 type_info objects for static initialization.
56 The type information VAR_DECL of a type is held on the
57 IDENTIFIER_GLOBAL_VALUE of the type's mangled name. That VAR_DECL
58 will be the internal type. It will usually have the correct
59 internal type reflecting the kind of type it represents (pointer,
60 array, function, class, inherited class, etc). When the type it
61 represents is incomplete, it will have the internal type
62 corresponding to type_info. That will only happen at the end of
63 translation, when we are emitting the type info objects. */
65 /* Accessors for the type_info objects. We need to remember several things
66 about each of the type_info types. The global tree nodes such as
67 bltn_desc_type_node are TREE_LISTs, and these macros are used to access
68 the required information. */
69 /* The RECORD_TYPE of a type_info derived class. */
70 #define TINFO_PSEUDO_TYPE(NODE) TREE_TYPE (NODE)
71 /* The VAR_DECL of the vtable for the type_info derived class.
72 This is only filled in at the end of the translation. */
73 #define TINFO_VTABLE_DECL(NODE) TREE_VALUE (NODE)
74 /* The IDENTIFIER_NODE naming the real class. */
75 #define TINFO_REAL_NAME(NODE) TREE_PURPOSE (NODE)
77 /* A varray of all tinfo decls that haven't yet been emitted. */
78 varray_type unemitted_tinfo_decls;
80 static tree build_headof (tree);
81 static tree ifnonnull (tree, tree);
82 static tree tinfo_name (tree);
83 static tree build_dynamic_cast_1 (tree, tree);
84 static tree throw_bad_cast (void);
85 static tree throw_bad_typeid (void);
86 static tree get_tinfo_decl_dynamic (tree);
87 static tree get_tinfo_ptr (tree);
88 static bool typeid_ok_p (void);
89 static int qualifier_flags (tree);
90 static bool target_incomplete_p (tree);
91 static tree tinfo_base_init (tree, tree);
92 static tree generic_initializer (tree, tree);
93 static tree ptr_initializer (tree, tree, bool *);
94 static tree ptm_initializer (tree, tree, bool *);
95 static tree dfs_class_hint_mark (tree, void *);
96 static tree dfs_class_hint_unmark (tree, void *);
97 static int class_hint_flags (tree);
98 static tree class_initializer (tree, tree, tree);
99 static tree create_pseudo_type_info (const char *, int, ...);
100 static tree get_pseudo_ti_init (tree, tree, bool *);
101 static tree get_pseudo_ti_desc (tree);
102 static void create_tinfo_types (void);
103 static bool typeinfo_in_lib_p (tree);
104 static bool unemitted_tinfo_decl_p (tree);
106 static int doing_runtime = 0;
109 /* Declare language defined type_info type and a pointer to const
110 type_info. This is incomplete here, and will be completed when
111 the user #includes <typeinfo>. There are language defined
112 restrictions on what can be done until that is included. Create
113 the internal versions of the ABI types. */
115 void
116 init_rtti_processing (void)
118 tree const_type_info_type;
120 push_namespace (std_identifier);
121 type_info_type_node
122 = xref_tag (class_type, get_identifier ("type_info"),
123 /*attributes=*/NULL_TREE, true, false);
124 pop_namespace ();
125 const_type_info_type = build_qualified_type (type_info_type_node,
126 TYPE_QUAL_CONST);
127 type_info_ptr_type = build_pointer_type (const_type_info_type);
128 type_info_ref_type = build_reference_type (const_type_info_type);
130 VARRAY_TREE_INIT (unemitted_tinfo_decls, 10, "RTTI decls");
132 create_tinfo_types ();
135 /* Given the expression EXP of type `class *', return the head of the
136 object pointed to by EXP with type cv void*, if the class has any
137 virtual functions (TYPE_POLYMORPHIC_P), else just return the
138 expression. */
140 static tree
141 build_headof (tree exp)
143 tree type = TREE_TYPE (exp);
144 tree offset;
145 tree index;
147 my_friendly_assert (TREE_CODE (type) == POINTER_TYPE, 20000112);
148 type = TREE_TYPE (type);
150 if (!TYPE_POLYMORPHIC_P (type))
151 return exp;
153 /* We use this a couple of times below, protect it. */
154 exp = save_expr (exp);
156 /* The offset-to-top field is at index -2 from the vptr. */
157 index = build_int_2 (-2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE, -1);
159 offset = build_vtbl_ref (build_indirect_ref (exp, NULL), index);
161 type = build_qualified_type (ptr_type_node,
162 cp_type_quals (TREE_TYPE (exp)));
163 return build (PLUS_EXPR, type, exp,
164 convert_to_integer (ptrdiff_type_node, offset));
167 /* Get a bad_cast node for the program to throw...
169 See libstdc++/exception.cc for __throw_bad_cast */
171 static tree
172 throw_bad_cast (void)
174 tree fn = get_identifier ("__cxa_bad_cast");
175 if (!get_global_value_if_present (fn, &fn))
176 fn = push_throw_library_fn (fn, build_function_type (ptr_type_node,
177 void_list_node));
179 return build_cxx_call (fn, NULL_TREE, NULL_TREE);
182 /* Return an expression for "__cxa_bad_typeid()". The expression
183 returned is an lvalue of type "const std::type_info". */
185 static tree
186 throw_bad_typeid (void)
188 tree fn = get_identifier ("__cxa_bad_typeid");
189 if (!get_global_value_if_present (fn, &fn))
191 tree t = build_qualified_type (type_info_type_node, TYPE_QUAL_CONST);
192 t = build_function_type (build_reference_type (t), void_list_node);
193 fn = push_throw_library_fn (fn, t);
196 return convert_from_reference (build_cxx_call (fn, NULL_TREE, NULL_TREE));
199 /* Return an lvalue expression whose type is "const std::type_info"
200 and whose value indicates the type of the expression EXP. If EXP
201 is a reference to a polymorphic class, return the dynamic type;
202 otherwise return the static type of the expression. */
204 static tree
205 get_tinfo_decl_dynamic (tree exp)
207 tree type;
208 tree t;
210 if (exp == error_mark_node)
211 return error_mark_node;
213 /* peel back references, so they match. */
214 type = non_reference (TREE_TYPE (exp));
216 /* Peel off cv qualifiers. */
217 type = TYPE_MAIN_VARIANT (type);
219 if (!VOID_TYPE_P (type))
220 type = complete_type_or_else (type, exp);
222 if (!type)
223 return error_mark_node;
225 /* If exp is a reference to polymorphic type, get the real type_info. */
226 if (TYPE_POLYMORPHIC_P (type) && ! resolves_to_fixed_type_p (exp, 0))
228 /* build reference to type_info from vtable. */
229 tree index;
231 /* The RTTI information is at index -1. */
232 index = build_int_2 (-1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE, -1);
233 t = build_vtbl_ref (exp, index);
234 TREE_TYPE (t) = type_info_ptr_type;
236 else
237 /* Otherwise return the type_info for the static type of the expr. */
238 t = get_tinfo_ptr (TYPE_MAIN_VARIANT (type));
240 return build_indirect_ref (t, NULL);
243 static bool
244 typeid_ok_p (void)
246 if (! flag_rtti)
248 error ("cannot use typeid with -fno-rtti");
249 return false;
252 if (!COMPLETE_TYPE_P (type_info_type_node))
254 error ("must #include <typeinfo> before using typeid");
255 return false;
258 return true;
261 /* Return an expression for "typeid(EXP)". The expression returned is
262 an lvalue of type "const std::type_info". */
264 tree
265 build_typeid (tree exp)
267 tree cond = NULL_TREE;
268 int nonnull = 0;
270 if (exp == error_mark_node || !typeid_ok_p ())
271 return error_mark_node;
273 if (processing_template_decl)
274 return build_min (TYPEID_EXPR, type_info_ref_type, exp);
276 if (TREE_CODE (exp) == INDIRECT_REF
277 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == POINTER_TYPE
278 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp))
279 && ! resolves_to_fixed_type_p (exp, &nonnull)
280 && ! nonnull)
282 exp = stabilize_reference (exp);
283 cond = cp_convert (boolean_type_node, TREE_OPERAND (exp, 0));
286 exp = get_tinfo_decl_dynamic (exp);
288 if (exp == error_mark_node)
289 return error_mark_node;
291 if (cond)
293 tree bad = throw_bad_typeid ();
295 exp = build (COND_EXPR, TREE_TYPE (exp), cond, exp, bad);
298 return exp;
301 /* Generate the NTBS name of a type. */
302 static tree
303 tinfo_name (tree type)
305 const char *name;
306 tree name_string;
308 name = mangle_type_string (type);
309 name_string = fix_string_type (build_string (strlen (name) + 1, name));
310 return name_string;
313 /* Return a VAR_DECL for the internal ABI defined type_info object for
314 TYPE. You must arrange that the decl is mark_used, if actually use
315 it --- decls in vtables are only used if the vtable is output. */
317 tree
318 get_tinfo_decl (tree type)
320 tree name;
321 tree d;
323 if (COMPLETE_TYPE_P (type)
324 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
326 error ("cannot create type information for type `%T' because its size is variable",
327 type);
328 return error_mark_node;
331 if (TREE_CODE (type) == METHOD_TYPE)
332 type = build_function_type (TREE_TYPE (type),
333 TREE_CHAIN (TYPE_ARG_TYPES (type)));
335 /* For a class type, the variable is cached in the type node
336 itself. */
337 if (CLASS_TYPE_P (type))
339 d = CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type));
340 if (d)
341 return d;
344 name = mangle_typeinfo_for_type (type);
346 d = IDENTIFIER_GLOBAL_VALUE (name);
347 if (!d)
349 tree var_desc = get_pseudo_ti_desc (type);
351 d = build_lang_decl (VAR_DECL, name, TINFO_PSEUDO_TYPE (var_desc));
353 DECL_ARTIFICIAL (d) = 1;
354 TREE_READONLY (d) = 1;
355 TREE_STATIC (d) = 1;
356 DECL_EXTERNAL (d) = 1;
357 DECL_COMDAT (d) = 1;
358 TREE_PUBLIC (d) = 1;
359 SET_DECL_ASSEMBLER_NAME (d, name);
361 pushdecl_top_level_and_finish (d, NULL_TREE);
363 if (CLASS_TYPE_P (type))
364 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type)) = d;
366 /* Remember the type it is for. */
367 TREE_TYPE (name) = type;
369 /* Add decl to the global array of tinfo decls. */
370 my_friendly_assert (unemitted_tinfo_decls != 0, 20030312);
371 VARRAY_PUSH_TREE (unemitted_tinfo_decls, d);
374 return d;
377 /* Return a pointer to a type_info object describing TYPE, suitably
378 cast to the language defined type. */
380 static tree
381 get_tinfo_ptr (tree type)
383 tree decl = get_tinfo_decl (type);
385 mark_used (decl);
386 return build_nop (type_info_ptr_type,
387 build_address (decl));
390 /* Return the type_info object for TYPE. */
392 tree
393 get_typeid (tree type)
395 if (type == error_mark_node || !typeid_ok_p ())
396 return error_mark_node;
398 if (processing_template_decl)
399 return build_min (TYPEID_EXPR, type_info_ref_type, type);
401 /* If the type of the type-id is a reference type, the result of the
402 typeid expression refers to a type_info object representing the
403 referenced type. */
404 type = non_reference (type);
406 /* The top-level cv-qualifiers of the lvalue expression or the type-id
407 that is the operand of typeid are always ignored. */
408 type = TYPE_MAIN_VARIANT (type);
410 if (!VOID_TYPE_P (type))
411 type = complete_type_or_else (type, NULL_TREE);
413 if (!type)
414 return error_mark_node;
416 return build_indirect_ref (get_tinfo_ptr (type), NULL);
419 /* Check whether TEST is null before returning RESULT. If TEST is used in
420 RESULT, it must have previously had a save_expr applied to it. */
422 static tree
423 ifnonnull (tree test, tree result)
425 return build (COND_EXPR, TREE_TYPE (result),
426 build (EQ_EXPR, boolean_type_node, test, integer_zero_node),
427 cp_convert (TREE_TYPE (result), integer_zero_node),
428 result);
431 /* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
432 paper. */
434 static tree
435 build_dynamic_cast_1 (tree type, tree expr)
437 enum tree_code tc = TREE_CODE (type);
438 tree exprtype = TREE_TYPE (expr);
439 tree dcast_fn;
440 tree old_expr = expr;
441 const char *errstr = NULL;
443 /* T shall be a pointer or reference to a complete class type, or
444 `pointer to cv void''. */
445 switch (tc)
447 case POINTER_TYPE:
448 if (TREE_CODE (TREE_TYPE (type)) == VOID_TYPE)
449 break;
450 case REFERENCE_TYPE:
451 if (! IS_AGGR_TYPE (TREE_TYPE (type)))
453 errstr = "target is not pointer or reference to class";
454 goto fail;
456 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type))))
458 errstr = "target is not pointer or reference to complete type";
459 goto fail;
461 break;
463 default:
464 errstr = "target is not pointer or reference";
465 goto fail;
468 if (tc == POINTER_TYPE)
469 expr = convert_from_reference (expr);
470 else if (TREE_CODE (exprtype) != REFERENCE_TYPE)
472 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
473 exprtype = build_reference_type (exprtype);
474 expr = convert_to_reference (exprtype, expr, CONV_IMPLICIT,
475 LOOKUP_NORMAL, NULL_TREE);
478 exprtype = TREE_TYPE (expr);
480 if (tc == POINTER_TYPE)
482 /* If T is a pointer type, v shall be an rvalue of a pointer to
483 complete class type, and the result is an rvalue of type T. */
485 if (TREE_CODE (exprtype) != POINTER_TYPE)
487 errstr = "source is not a pointer";
488 goto fail;
490 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
492 errstr = "source is not a pointer to class";
493 goto fail;
495 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
497 errstr = "source is a pointer to incomplete type";
498 goto fail;
501 else
503 /* T is a reference type, v shall be an lvalue of a complete class
504 type, and the result is an lvalue of the type referred to by T. */
506 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
508 errstr = "source is not of class type";
509 goto fail;
511 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
513 errstr = "source is of incomplete class type";
514 goto fail;
519 /* The dynamic_cast operator shall not cast away constness. */
520 if (!at_least_as_qualified_p (TREE_TYPE (type),
521 TREE_TYPE (exprtype)))
523 errstr = "conversion casts away constness";
524 goto fail;
527 /* If *type is an unambiguous accessible base class of *exprtype,
528 convert statically. */
530 tree binfo;
532 binfo = lookup_base (TREE_TYPE (exprtype), TREE_TYPE (type),
533 ba_not_special, NULL);
535 if (binfo)
537 expr = build_base_path (PLUS_EXPR, convert_from_reference (expr),
538 binfo, 0);
539 if (TREE_CODE (exprtype) == POINTER_TYPE)
540 expr = non_lvalue (expr);
541 return expr;
545 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
546 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype)))
548 tree expr1;
549 /* if TYPE is `void *', return pointer to complete object. */
550 if (tc == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (type)))
552 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
553 if (TREE_CODE (expr) == ADDR_EXPR
554 && TREE_CODE (TREE_OPERAND (expr, 0)) == VAR_DECL
555 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE)
556 return build1 (NOP_EXPR, type, expr);
558 /* Since expr is used twice below, save it. */
559 expr = save_expr (expr);
561 expr1 = build_headof (expr);
562 if (TREE_TYPE (expr1) != type)
563 expr1 = build1 (NOP_EXPR, type, expr1);
564 return ifnonnull (expr, expr1);
566 else
568 tree retval;
569 tree result, td2, td3, elems;
570 tree static_type, target_type, boff;
572 /* If we got here, we can't convert statically. Therefore,
573 dynamic_cast<D&>(b) (b an object) cannot succeed. */
574 if (tc == REFERENCE_TYPE)
576 if (TREE_CODE (old_expr) == VAR_DECL
577 && TREE_CODE (TREE_TYPE (old_expr)) == RECORD_TYPE)
579 tree expr = throw_bad_cast ();
580 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
581 old_expr, type);
582 /* Bash it to the expected type. */
583 TREE_TYPE (expr) = type;
584 return expr;
587 /* Ditto for dynamic_cast<D*>(&b). */
588 else if (TREE_CODE (expr) == ADDR_EXPR)
590 tree op = TREE_OPERAND (expr, 0);
591 if (TREE_CODE (op) == VAR_DECL
592 && TREE_CODE (TREE_TYPE (op)) == RECORD_TYPE)
594 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
595 op, type);
596 retval = build_int_2 (0, 0);
597 TREE_TYPE (retval) = type;
598 return retval;
602 target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
603 static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
604 td2 = get_tinfo_decl (target_type);
605 mark_used (td2);
606 td2 = build_unary_op (ADDR_EXPR, td2, 0);
607 td3 = get_tinfo_decl (static_type);
608 mark_used (td3);
609 td3 = build_unary_op (ADDR_EXPR, td3, 0);
611 /* Determine how T and V are related. */
612 boff = get_dynamic_cast_base_type (static_type, target_type);
614 /* Since expr is used twice below, save it. */
615 expr = save_expr (expr);
617 expr1 = expr;
618 if (tc == REFERENCE_TYPE)
619 expr1 = build_unary_op (ADDR_EXPR, expr1, 0);
621 elems = tree_cons
622 (NULL_TREE, expr1, tree_cons
623 (NULL_TREE, td3, tree_cons
624 (NULL_TREE, td2, tree_cons
625 (NULL_TREE, boff, NULL_TREE))));
627 dcast_fn = dynamic_cast_node;
628 if (!dcast_fn)
630 tree tmp;
631 tree tinfo_ptr;
632 tree ns = abi_node;
633 const char *name;
635 push_nested_namespace (ns);
636 tinfo_ptr = xref_tag (class_type,
637 get_identifier ("__class_type_info"),
638 /*attributes=*/NULL_TREE,
639 true, false);
641 tinfo_ptr = build_pointer_type
642 (build_qualified_type
643 (tinfo_ptr, TYPE_QUAL_CONST));
644 name = "__dynamic_cast";
645 tmp = tree_cons
646 (NULL_TREE, const_ptr_type_node, tree_cons
647 (NULL_TREE, tinfo_ptr, tree_cons
648 (NULL_TREE, tinfo_ptr, tree_cons
649 (NULL_TREE, ptrdiff_type_node, void_list_node))));
650 tmp = build_function_type (ptr_type_node, tmp);
651 dcast_fn = build_library_fn_ptr (name, tmp);
652 DECL_IS_PURE (dcast_fn) = 1;
653 pop_nested_namespace (ns);
654 dynamic_cast_node = dcast_fn;
656 result = build_cxx_call (dcast_fn, elems, elems);
658 if (tc == REFERENCE_TYPE)
660 tree bad = throw_bad_cast ();
662 result = save_expr (result);
663 return build (COND_EXPR, type, result, result, bad);
666 /* Now back to the type we want from a void*. */
667 result = cp_convert (type, result);
668 return ifnonnull (expr, result);
671 else
672 errstr = "source type is not polymorphic";
674 fail:
675 error ("cannot dynamic_cast `%E' (of type `%#T') to type `%#T' (%s)",
676 expr, exprtype, type, errstr);
677 return error_mark_node;
680 tree
681 build_dynamic_cast (tree type, tree expr)
683 if (type == error_mark_node || expr == error_mark_node)
684 return error_mark_node;
686 if (processing_template_decl)
688 expr = build_min (DYNAMIC_CAST_EXPR, type, expr);
689 TREE_SIDE_EFFECTS (expr) = 1;
691 return expr;
694 return convert_from_reference (build_dynamic_cast_1 (type, expr));
697 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
699 static int
700 qualifier_flags (tree type)
702 int flags = 0;
703 int quals = cp_type_quals (type);
705 if (quals & TYPE_QUAL_CONST)
706 flags |= 1;
707 if (quals & TYPE_QUAL_VOLATILE)
708 flags |= 2;
709 if (quals & TYPE_QUAL_RESTRICT)
710 flags |= 4;
711 return flags;
714 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
715 contains a pointer to member of an incomplete class. */
717 static bool
718 target_incomplete_p (tree type)
720 while (true)
721 if (TYPE_PTRMEM_P (type))
723 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type)))
724 return true;
725 type = TYPE_PTRMEM_POINTED_TO_TYPE (type);
727 else if (TREE_CODE (type) == POINTER_TYPE)
728 type = TREE_TYPE (type);
729 else
730 return !COMPLETE_OR_VOID_TYPE_P (type);
733 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
734 is the vtable pointer and NTBS name. The NTBS name is emitted as a
735 comdat const char array, so it becomes a unique key for the type. Generate
736 and emit that VAR_DECL here. (We can't always emit the type_info itself
737 as comdat, because of pointers to incomplete.) */
739 static tree
740 tinfo_base_init (tree desc, tree target)
742 tree init = NULL_TREE;
743 tree name_decl;
744 tree vtable_ptr;
747 tree name_name;
749 /* Generate the NTBS array variable. */
750 tree name_type = build_cplus_array_type
751 (build_qualified_type (char_type_node, TYPE_QUAL_CONST),
752 NULL_TREE);
753 tree name_string = tinfo_name (target);
755 name_name = mangle_typeinfo_string_for_type (target);
756 name_decl = build_lang_decl (VAR_DECL, name_name, name_type);
758 DECL_ARTIFICIAL (name_decl) = 1;
759 TREE_READONLY (name_decl) = 1;
760 TREE_STATIC (name_decl) = 1;
761 DECL_EXTERNAL (name_decl) = 0;
762 TREE_PUBLIC (name_decl) = 1;
763 import_export_tinfo (name_decl, target, typeinfo_in_lib_p (target));
764 /* External name of the string containing the type's name has a
765 special name. */
766 SET_DECL_ASSEMBLER_NAME (name_decl,
767 mangle_typeinfo_string_for_type (target));
768 DECL_INITIAL (name_decl) = name_string;
769 mark_used (name_decl);
770 pushdecl_top_level_and_finish (name_decl, name_string);
773 vtable_ptr = TINFO_VTABLE_DECL (desc);
774 if (!vtable_ptr)
776 tree real_type;
778 push_nested_namespace (abi_node);
779 real_type = xref_tag (class_type, TINFO_REAL_NAME (desc),
780 /*attributes=*/NULL_TREE, true, false);
781 pop_nested_namespace (abi_node);
783 if (!COMPLETE_TYPE_P (real_type))
785 /* We never saw a definition of this type, so we need to
786 tell the compiler that this is an exported class, as
787 indeed all of the __*_type_info classes are. */
788 SET_CLASSTYPE_INTERFACE_KNOWN (real_type);
789 CLASSTYPE_INTERFACE_ONLY (real_type) = 1;
792 vtable_ptr = get_vtable_decl (real_type, /*complete=*/1);
793 vtable_ptr = build_unary_op (ADDR_EXPR, vtable_ptr, 0);
795 /* We need to point into the middle of the vtable. */
796 vtable_ptr = build
797 (PLUS_EXPR, TREE_TYPE (vtable_ptr), vtable_ptr,
798 size_binop (MULT_EXPR,
799 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE),
800 TYPE_SIZE_UNIT (vtable_entry_type)));
801 TREE_CONSTANT (vtable_ptr) = 1;
803 TINFO_VTABLE_DECL (desc) = vtable_ptr;
806 init = tree_cons (NULL_TREE, vtable_ptr, init);
808 init = tree_cons (NULL_TREE, decay_conversion (name_decl), init);
810 init = build_constructor (NULL_TREE, nreverse (init));
811 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
812 init = tree_cons (NULL_TREE, init, NULL_TREE);
814 return init;
817 /* Return the CONSTRUCTOR expr for a type_info of TYPE. DESC provides the
818 information about the particular type_info derivation, which adds no
819 additional fields to the type_info base. */
821 static tree
822 generic_initializer (tree desc, tree target)
824 tree init = tinfo_base_init (desc, target);
826 init = build_constructor (NULL_TREE, init);
827 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
828 return init;
831 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
832 DESC provides information about the particular type_info derivation,
833 which adds target type and qualifier flags members to the type_info base. */
835 static tree
836 ptr_initializer (tree desc, tree target, bool *non_public_ptr)
838 tree init = tinfo_base_init (desc, target);
839 tree to = TREE_TYPE (target);
840 int flags = qualifier_flags (to);
841 bool incomplete = target_incomplete_p (to);
843 if (incomplete)
845 flags |= 8;
846 *non_public_ptr = true;
848 init = tree_cons (NULL_TREE, build_int_2 (flags, 0), init);
849 init = tree_cons (NULL_TREE,
850 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
851 init);
853 init = build_constructor (NULL_TREE, nreverse (init));
854 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
855 return init;
858 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
859 DESC provides information about the particular type_info derivation,
860 which adds class, target type and qualifier flags members to the type_info
861 base. */
863 static tree
864 ptm_initializer (tree desc, tree target, bool *non_public_ptr)
866 tree init = tinfo_base_init (desc, target);
867 tree to = TYPE_PTRMEM_POINTED_TO_TYPE (target);
868 tree klass = TYPE_PTRMEM_CLASS_TYPE (target);
869 int flags = qualifier_flags (to);
870 bool incomplete = target_incomplete_p (to);
872 if (incomplete)
874 flags |= 0x8;
875 *non_public_ptr = true;
877 if (!COMPLETE_TYPE_P (klass))
879 flags |= 0x10;
880 *non_public_ptr = true;
882 init = tree_cons (NULL_TREE, build_int_2 (flags, 0), init);
883 init = tree_cons (NULL_TREE,
884 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
885 init);
886 init = tree_cons (NULL_TREE,
887 get_tinfo_ptr (klass),
888 init);
890 init = build_constructor (NULL_TREE, nreverse (init));
891 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
892 return init;
895 /* Check base BINFO to set hint flags in *DATA, which is really an int.
896 We use CLASSTYPE_MARKED to tag types we've found as non-virtual bases and
897 CLASSTYPE_MARKED2 to tag those which are virtual bases. Remember it is
898 possible for a type to be both a virtual and non-virtual base. */
900 static tree
901 dfs_class_hint_mark (tree binfo, void *data)
903 tree basetype = BINFO_TYPE (binfo);
904 int *hint = (int *) data;
906 if (TREE_VIA_VIRTUAL (binfo))
908 if (CLASSTYPE_MARKED (basetype))
909 *hint |= 1;
910 if (CLASSTYPE_MARKED2 (basetype))
911 *hint |= 2;
912 SET_CLASSTYPE_MARKED2 (basetype);
914 else
916 if (CLASSTYPE_MARKED (basetype) || CLASSTYPE_MARKED2 (basetype))
917 *hint |= 1;
918 SET_CLASSTYPE_MARKED (basetype);
920 return NULL_TREE;
923 /* Clear the base's dfs marks, after searching for duplicate bases. */
925 static tree
926 dfs_class_hint_unmark (tree binfo, void *data ATTRIBUTE_UNUSED)
928 tree basetype = BINFO_TYPE (binfo);
930 CLEAR_CLASSTYPE_MARKED (basetype);
931 CLEAR_CLASSTYPE_MARKED2 (basetype);
932 return NULL_TREE;
935 /* Determine the hint flags describing the features of a class's hierarchy. */
937 static int
938 class_hint_flags (tree type)
940 int hint_flags = 0;
942 dfs_walk (TYPE_BINFO (type), dfs_class_hint_mark, NULL, &hint_flags);
943 dfs_walk (TYPE_BINFO (type), dfs_class_hint_unmark, NULL, NULL);
945 return hint_flags;
948 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
949 DESC provides information about the particular __class_type_info derivation,
950 which adds hint flags and TRAIL initializers to the type_info base. */
952 static tree
953 class_initializer (tree desc, tree target, tree trail)
955 tree init = tinfo_base_init (desc, target);
957 TREE_CHAIN (init) = trail;
958 init = build_constructor (NULL_TREE, init);
959 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
960 return init;
963 /* Returns true if the typeinfo for type should be placed in
964 the runtime library. */
966 static bool
967 typeinfo_in_lib_p (tree type)
969 /* The typeinfo objects for `T*' and `const T*' are in the runtime
970 library for simple types T. */
971 if (TREE_CODE (type) == POINTER_TYPE
972 && (cp_type_quals (TREE_TYPE (type)) == TYPE_QUAL_CONST
973 || cp_type_quals (TREE_TYPE (type)) == TYPE_UNQUALIFIED))
974 type = TREE_TYPE (type);
976 switch (TREE_CODE (type))
978 case INTEGER_TYPE:
979 case BOOLEAN_TYPE:
980 case CHAR_TYPE:
981 case REAL_TYPE:
982 case VOID_TYPE:
983 return true;
985 default:
986 return false;
990 /* Generate the initializer for the type info describing
991 TYPE. VAR_DESC is a . NON_PUBLIC_P is set nonzero, if the VAR_DECL
992 should not be exported from this object file. This should only be
993 called at the end of translation, when we know that no further
994 types will be completed. */
996 static tree
997 get_pseudo_ti_init (tree type, tree var_desc, bool *non_public_p)
999 my_friendly_assert (at_eof, 20021120);
1000 switch (TREE_CODE (type))
1002 case OFFSET_TYPE:
1003 return ptm_initializer (var_desc, type, non_public_p);
1004 case POINTER_TYPE:
1005 return ptr_initializer (var_desc, type, non_public_p);
1006 case ENUMERAL_TYPE:
1007 return generic_initializer (var_desc, type);
1008 break;
1009 case FUNCTION_TYPE:
1010 return generic_initializer (var_desc, type);
1011 break;
1012 case ARRAY_TYPE:
1013 return generic_initializer (var_desc, type);
1014 break;
1015 case UNION_TYPE:
1016 case RECORD_TYPE:
1017 if (TYPE_PTRMEMFUNC_P (type))
1018 return ptm_initializer (var_desc, type, non_public_p);
1019 else if (var_desc == class_desc_type_node)
1021 if (!COMPLETE_TYPE_P (type))
1022 /* Emit a non-public class_type_info. */
1023 *non_public_p = true;
1024 return class_initializer (var_desc, type, NULL_TREE);
1026 else if (var_desc == si_class_desc_type_node)
1028 tree base_binfos = BINFO_BASETYPES (TYPE_BINFO (type));
1029 tree base_binfo = TREE_VEC_ELT (base_binfos, 0);
1030 tree tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1031 tree base_inits = tree_cons (NULL_TREE, tinfo, NULL_TREE);
1033 return class_initializer (var_desc, type, base_inits);
1035 else
1037 int hint = class_hint_flags (type);
1038 tree binfo = TYPE_BINFO (type);
1039 int nbases = BINFO_N_BASETYPES (binfo);
1040 tree base_binfos = BINFO_BASETYPES (binfo);
1041 tree base_accesses = BINFO_BASEACCESSES (binfo);
1042 tree base_inits = NULL_TREE;
1043 int ix;
1045 /* Generate the base information initializer. */
1046 for (ix = nbases; ix--;)
1048 tree base_binfo = TREE_VEC_ELT (base_binfos, ix);
1049 tree base_init = NULL_TREE;
1050 int flags = 0;
1051 tree tinfo;
1052 tree offset;
1054 if (TREE_VEC_ELT (base_accesses, ix) == access_public_node)
1055 flags |= 2;
1056 tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1057 if (TREE_VIA_VIRTUAL (base_binfo))
1059 /* We store the vtable offset at which the virtual
1060 base offset can be found. */
1061 offset = BINFO_VPTR_FIELD (base_binfo);
1062 offset = convert (sizetype, offset);
1063 flags |= 1;
1065 else
1066 offset = BINFO_OFFSET (base_binfo);
1068 /* Combine offset and flags into one field. */
1069 offset = cp_build_binary_op (LSHIFT_EXPR, offset,
1070 build_int_2 (8, 0));
1071 offset = cp_build_binary_op (BIT_IOR_EXPR, offset,
1072 build_int_2 (flags, 0));
1073 base_init = tree_cons (NULL_TREE, offset, base_init);
1074 base_init = tree_cons (NULL_TREE, tinfo, base_init);
1075 base_init = build_constructor (NULL_TREE, base_init);
1076 TREE_HAS_CONSTRUCTOR (base_init) = 1;
1077 base_inits = tree_cons (NULL_TREE, base_init, base_inits);
1079 base_inits = build_constructor (NULL_TREE, base_inits);
1080 TREE_HAS_CONSTRUCTOR (base_inits) = 1;
1081 base_inits = tree_cons (NULL_TREE, base_inits, NULL_TREE);
1082 /* Prepend the number of bases. */
1083 base_inits = tree_cons (NULL_TREE,
1084 build_int_2 (nbases, 0), base_inits);
1085 /* Prepend the hint flags. */
1086 base_inits = tree_cons (NULL_TREE,
1087 build_int_2 (hint, 0), base_inits);
1089 return class_initializer (var_desc, type, base_inits);
1091 break;
1093 default:
1094 return generic_initializer (var_desc, type);
1098 /* Generate the RECORD_TYPE containing the data layout of a type_info
1099 derivative as used by the runtime. This layout must be consistent with
1100 that defined in the runtime support. Also generate the VAR_DECL for the
1101 type's vtable. We explicitly manage the vtable member, and name it for
1102 real type as used in the runtime. The RECORD type has a different name,
1103 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1104 is the generated type and TINFO_VTABLE_NAME is the name of the
1105 vtable. We have to delay generating the VAR_DECL of the vtable
1106 until the end of the translation, when we'll have seen the library
1107 definition, if there was one.
1109 REAL_NAME is the runtime's name of the type. Trailing arguments are
1110 additional FIELD_DECL's for the structure. The final argument must be
1111 NULL. */
1113 static tree
1114 create_pseudo_type_info (const char *real_name, int ident, ...)
1116 tree pseudo_type;
1117 char *pseudo_name;
1118 tree fields;
1119 tree field_decl;
1120 tree result;
1121 va_list ap;
1123 va_start (ap, ident);
1125 /* Generate the pseudo type name. */
1126 pseudo_name = alloca (strlen (real_name) + 30);
1127 strcpy (pseudo_name, real_name);
1128 strcat (pseudo_name, "_pseudo");
1129 if (ident)
1130 sprintf (pseudo_name + strlen (pseudo_name), "%d", ident);
1132 /* First field is the pseudo type_info base class. */
1133 fields = build_decl (FIELD_DECL, NULL_TREE, ti_desc_type_node);
1135 /* Now add the derived fields. */
1136 while ((field_decl = va_arg (ap, tree)))
1138 TREE_CHAIN (field_decl) = fields;
1139 fields = field_decl;
1142 /* Create the pseudo type. */
1143 pseudo_type = make_aggr_type (RECORD_TYPE);
1144 finish_builtin_struct (pseudo_type, pseudo_name, fields, NULL_TREE);
1145 CLASSTYPE_AS_BASE (pseudo_type) = pseudo_type;
1147 result = tree_cons (NULL_TREE, NULL_TREE, NULL_TREE);
1148 TINFO_REAL_NAME (result) = get_identifier (real_name);
1149 TINFO_PSEUDO_TYPE (result) =
1150 cp_build_qualified_type (pseudo_type, TYPE_QUAL_CONST);
1152 va_end (ap);
1153 return result;
1156 /* Return a pseudo type info type node used to describe TYPE. TYPE
1157 must be a complete type (or cv void), except at the end of the
1158 translation unit. */
1160 static tree
1161 get_pseudo_ti_desc (tree type)
1163 switch (TREE_CODE (type))
1165 case OFFSET_TYPE:
1166 return ptm_desc_type_node;
1167 case POINTER_TYPE:
1168 return ptr_desc_type_node;
1169 case ENUMERAL_TYPE:
1170 return enum_desc_type_node;
1171 case FUNCTION_TYPE:
1172 return func_desc_type_node;
1173 case ARRAY_TYPE:
1174 return ary_desc_type_node;
1175 case UNION_TYPE:
1176 case RECORD_TYPE:
1177 if (TYPE_PTRMEMFUNC_P (type))
1178 return ptm_desc_type_node;
1179 else if (!COMPLETE_TYPE_P (type))
1181 if (!at_eof)
1182 cxx_incomplete_type_error (NULL_TREE, type);
1183 return class_desc_type_node;
1185 else if (!CLASSTYPE_N_BASECLASSES (type))
1186 return class_desc_type_node;
1187 else
1189 tree binfo = TYPE_BINFO (type);
1190 tree base_binfos = BINFO_BASETYPES (binfo);
1191 tree base_accesses = BINFO_BASEACCESSES (binfo);
1192 tree base_binfo = TREE_VEC_ELT (base_binfos, 0);
1193 int num_bases = TREE_VEC_LENGTH (base_binfos);
1195 if (num_bases == 1
1196 && TREE_VEC_ELT (base_accesses, 0) == access_public_node
1197 && !TREE_VIA_VIRTUAL (base_binfo)
1198 && integer_zerop (BINFO_OFFSET (base_binfo)))
1199 /* single non-virtual public. */
1200 return si_class_desc_type_node;
1201 else
1203 tree var_desc;
1204 tree array_domain, base_array;
1206 if (TREE_VEC_LENGTH (vmi_class_desc_type_node) <= num_bases)
1208 int ix;
1209 tree extend = make_tree_vec (num_bases + 5);
1211 for (ix = TREE_VEC_LENGTH (vmi_class_desc_type_node); ix--;)
1212 TREE_VEC_ELT (extend, ix)
1213 = TREE_VEC_ELT (vmi_class_desc_type_node, ix);
1214 vmi_class_desc_type_node = extend;
1216 var_desc = TREE_VEC_ELT (vmi_class_desc_type_node, num_bases);
1217 if (var_desc)
1218 return var_desc;
1220 /* Create the array of __base_class_type_info entries.
1221 G++ 3.2 allocated an array that had one too many
1222 entries, and then filled that extra entries with
1223 zeros. */
1224 if (abi_version_at_least (2))
1225 array_domain = build_index_type (size_int (num_bases - 1));
1226 else
1227 array_domain = build_index_type (size_int (num_bases));
1228 base_array =
1229 build_array_type (base_desc_type_node, array_domain);
1231 push_nested_namespace (abi_node);
1232 var_desc = create_pseudo_type_info
1233 ("__vmi_class_type_info", num_bases,
1234 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1235 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1236 build_decl (FIELD_DECL, NULL_TREE, base_array),
1237 NULL);
1238 pop_nested_namespace (abi_node);
1240 TREE_VEC_ELT (vmi_class_desc_type_node, num_bases) = var_desc;
1241 return var_desc;
1244 default:
1245 return bltn_desc_type_node;
1249 /* Make sure the required builtin types exist for generating the type_info
1250 varable definitions. */
1252 static void
1253 create_tinfo_types (void)
1255 my_friendly_assert (!ti_desc_type_node, 20020609);
1257 push_nested_namespace (abi_node);
1259 /* Create the internal type_info structure. This is used as a base for
1260 the other structures. */
1262 tree field, fields;
1264 ti_desc_type_node = make_aggr_type (RECORD_TYPE);
1265 field = build_decl (FIELD_DECL, NULL_TREE, const_ptr_type_node);
1266 fields = field;
1268 field = build_decl (FIELD_DECL, NULL_TREE, const_string_type_node);
1269 TREE_CHAIN (field) = fields;
1270 fields = field;
1272 finish_builtin_struct (ti_desc_type_node, "__type_info_pseudo",
1273 fields, NULL_TREE);
1274 TYPE_HAS_CONSTRUCTOR (ti_desc_type_node) = 1;
1277 /* Fundamental type_info */
1278 bltn_desc_type_node = create_pseudo_type_info
1279 ("__fundamental_type_info", 0,
1280 NULL);
1282 /* Array, function and enum type_info. No additional fields. */
1283 ary_desc_type_node = create_pseudo_type_info
1284 ("__array_type_info", 0,
1285 NULL);
1286 func_desc_type_node = create_pseudo_type_info
1287 ("__function_type_info", 0,
1288 NULL);
1289 enum_desc_type_node = create_pseudo_type_info
1290 ("__enum_type_info", 0,
1291 NULL);
1293 /* Class type_info. Add a flags field. */
1294 class_desc_type_node = create_pseudo_type_info
1295 ("__class_type_info", 0,
1296 NULL);
1298 /* Single public non-virtual base class. Add pointer to base class.
1299 This is really a descendant of __class_type_info. */
1300 si_class_desc_type_node = create_pseudo_type_info
1301 ("__si_class_type_info", 0,
1302 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1303 NULL);
1305 /* Base class internal helper. Pointer to base type, offset to base,
1306 flags. */
1308 tree field, fields;
1310 field = build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type);
1311 fields = field;
1313 field = build_decl (FIELD_DECL, NULL_TREE, integer_types[itk_long]);
1314 TREE_CHAIN (field) = fields;
1315 fields = field;
1317 base_desc_type_node = make_aggr_type (RECORD_TYPE);
1318 finish_builtin_struct (base_desc_type_node, "__base_class_type_info_pseudo",
1319 fields, NULL_TREE);
1320 TYPE_HAS_CONSTRUCTOR (base_desc_type_node) = 1;
1323 /* General hierarchy is created as necessary in this vector. */
1324 vmi_class_desc_type_node = make_tree_vec (10);
1326 /* Pointer type_info. Adds two fields, qualification mask
1327 and pointer to the pointed to type. This is really a descendant of
1328 __pbase_type_info. */
1329 ptr_desc_type_node = create_pseudo_type_info
1330 ("__pointer_type_info", 0,
1331 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1332 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1333 NULL);
1335 /* Pointer to member data type_info. Add qualifications flags,
1336 pointer to the member's type info and pointer to the class.
1337 This is really a descendant of __pbase_type_info. */
1338 ptm_desc_type_node = create_pseudo_type_info
1339 ("__pointer_to_member_type_info", 0,
1340 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1341 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1342 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1343 NULL);
1345 pop_nested_namespace (abi_node);
1348 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1349 support. Generating them here guarantees consistency with the other
1350 structures. We use the following heuristic to determine when the runtime
1351 is being generated. If std::__fundamental_type_info is defined, and its
1352 destructor is defined, then the runtime is being built. */
1354 void
1355 emit_support_tinfos (void)
1357 static tree *const fundamentals[] =
1359 &void_type_node,
1360 &boolean_type_node,
1361 &wchar_type_node,
1362 &char_type_node, &signed_char_type_node, &unsigned_char_type_node,
1363 &short_integer_type_node, &short_unsigned_type_node,
1364 &integer_type_node, &unsigned_type_node,
1365 &long_integer_type_node, &long_unsigned_type_node,
1366 &long_long_integer_type_node, &long_long_unsigned_type_node,
1367 &float_type_node, &double_type_node, &long_double_type_node,
1370 int ix;
1371 tree bltn_type, dtor;
1373 push_nested_namespace (abi_node);
1374 bltn_type = xref_tag (class_type,
1375 get_identifier ("__fundamental_type_info"),
1376 /*attributes=*/NULL_TREE,
1377 true, false);
1378 pop_nested_namespace (abi_node);
1379 if (!COMPLETE_TYPE_P (bltn_type))
1380 return;
1381 dtor = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (bltn_type), 1);
1382 if (DECL_EXTERNAL (dtor))
1383 return;
1384 doing_runtime = 1;
1385 for (ix = 0; fundamentals[ix]; ix++)
1387 tree bltn = *fundamentals[ix];
1388 tree bltn_ptr = build_pointer_type (bltn);
1389 tree bltn_const_ptr = build_pointer_type
1390 (build_qualified_type (bltn, TYPE_QUAL_CONST));
1391 tree tinfo;
1393 tinfo = get_tinfo_decl (bltn);
1394 TREE_USED (tinfo) = 1;
1395 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1397 tinfo = get_tinfo_decl (bltn_ptr);
1398 TREE_USED (tinfo) = 1;
1399 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1401 tinfo = get_tinfo_decl (bltn_const_ptr);
1402 TREE_USED (tinfo) = 1;
1403 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1407 /* Return true, iff T is a type_info variable which has not had a
1408 definition emitted for it. */
1410 static bool
1411 unemitted_tinfo_decl_p (tree t)
1413 if (/* It's a var decl */
1414 TREE_CODE (t) == VAR_DECL
1415 /* which has a name */
1416 && DECL_NAME (t)
1417 /* whose name points back to itself */
1418 && IDENTIFIER_GLOBAL_VALUE (DECL_NAME (t)) == t
1419 /* whose name's type is non-null */
1420 && TREE_TYPE (DECL_NAME (t))
1421 /* and whose type is a struct */
1422 && TREE_CODE (TREE_TYPE (t)) == RECORD_TYPE
1423 /* with a field */
1424 && TYPE_FIELDS (TREE_TYPE (t))
1425 /* which is our pseudo type info */
1426 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (t))) == ti_desc_type_node)
1427 return true;
1428 return false;
1431 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1432 tinfo decl. Determine whether it needs emitting, and if so
1433 generate the initializer. */
1435 bool
1436 emit_tinfo_decl (tree decl)
1438 tree type = TREE_TYPE (DECL_NAME (decl));
1439 bool non_public;
1440 int in_library = typeinfo_in_lib_p (type);
1441 tree var_desc, var_init;
1443 my_friendly_assert (unemitted_tinfo_decl_p (decl), 20030307);
1445 import_export_tinfo (decl, type, in_library);
1446 if (DECL_REALLY_EXTERN (decl) || !DECL_NEEDED_P (decl))
1447 return false;
1449 if (!doing_runtime && in_library)
1450 return false;
1452 non_public = false;
1453 var_desc = get_pseudo_ti_desc (type);
1454 var_init = get_pseudo_ti_init (type, var_desc, &non_public);
1456 DECL_EXTERNAL (decl) = 0;
1457 TREE_PUBLIC (decl) = !non_public;
1458 if (non_public)
1459 DECL_COMDAT (decl) = 0;
1461 DECL_INITIAL (decl) = var_init;
1462 mark_used (decl);
1463 cp_finish_decl (decl, var_init, NULL_TREE, 0);
1464 /* cp_finish_decl will have dealt with linkage. */
1466 /* Say we've dealt with it. */
1467 TREE_TYPE (DECL_NAME (decl)) = NULL_TREE;
1469 return true;