1 /* RunTime Type Identification
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
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)
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. */
26 #include "coretypes.h"
35 /* C++ returns type information to the user in struct type_info
36 objects. We also use type information to implement dynamic_cast and
37 exception handlers. Type information for a particular type is
38 indicated with an ABI defined structure derived from type_info.
39 This would all be very straight forward, but for the fact that the
40 runtime library provides the definitions of the type_info structure
41 and the ABI defined derived classes. We cannot build declarations
42 of them directly in the compiler, but we need to layout objects of
43 their type. Somewhere we have to lie.
45 We define layout compatible POD-structs with compiler-defined names
46 and generate the appropriate initializations for them (complete
47 with explicit mention of their vtable). When we have to provide a
48 type_info to the user we reinterpret_cast the internal compiler
49 type to type_info. A well formed program can only explicitly refer
50 to the type_infos of complete types (& cv void). However, we chain
51 pointer type_infos to the pointed-to-type, and that can be
52 incomplete. We only need the addresses of such incomplete
53 type_info objects for static initialization.
55 The type information VAR_DECL of a type is held on the
56 IDENTIFIER_GLOBAL_VALUE of the type's mangled name. That VAR_DECL
57 will be the internal type. It will usually have the correct
58 internal type reflecting the kind of type it represents (pointer,
59 array, function, class, inherited class, etc). When the type it
60 represents is incomplete, it will have the internal type
61 corresponding to type_info. That will only happen at the end of
62 translation, when we are emitting the type info objects. */
64 /* Accessors for the type_info objects. We need to remember several things
65 about each of the type_info types. The global tree nodes such as
66 bltn_desc_type_node are TREE_LISTs, and these macros are used to access
67 the required information. */
68 /* The RECORD_TYPE of a type_info derived class. */
69 #define TINFO_PSEUDO_TYPE(NODE) TREE_TYPE (NODE)
70 /* The VAR_DECL of the vtable for the type_info derived class.
71 This is only filled in at the end of the translation. */
72 #define TINFO_VTABLE_DECL(NODE) TREE_VALUE (NODE)
73 /* The IDENTIFIER_NODE naming the real class. */
74 #define TINFO_REAL_NAME(NODE) TREE_PURPOSE (NODE)
76 /* A varray of all tinfo decls that haven't yet been emitted. */
77 varray_type unemitted_tinfo_decls;
79 static tree build_headof (tree);
80 static tree ifnonnull (tree, tree);
81 static tree tinfo_name (tree);
82 static tree build_dynamic_cast_1 (tree, tree);
83 static tree throw_bad_cast (void);
84 static tree throw_bad_typeid (void);
85 static tree get_tinfo_decl_dynamic (tree);
86 static tree get_tinfo_ptr (tree);
87 static bool typeid_ok_p (void);
88 static int qualifier_flags (tree);
89 static bool target_incomplete_p (tree);
90 static tree tinfo_base_init (tree, tree);
91 static tree generic_initializer (tree, tree);
92 static tree ptr_initializer (tree, tree, bool *);
93 static tree ptm_initializer (tree, tree, bool *);
94 static tree dfs_class_hint_mark (tree, void *);
95 static tree dfs_class_hint_unmark (tree, void *);
96 static int class_hint_flags (tree);
97 static tree class_initializer (tree, tree, tree);
98 static tree create_pseudo_type_info (const char *, int, ...);
99 static tree get_pseudo_ti_init (tree, tree, bool *);
100 static tree get_pseudo_ti_desc (tree);
101 static void create_tinfo_types (void);
102 static bool typeinfo_in_lib_p (tree);
103 static bool unemitted_tinfo_decl_p (tree);
105 static int doing_runtime = 0;
108 /* Declare language defined type_info type and a pointer to const
109 type_info. This is incomplete here, and will be completed when
110 the user #includes <typeinfo>. There are language defined
111 restrictions on what can be done until that is included. Create
112 the internal versions of the ABI types. */
115 init_rtti_processing (void)
117 tree const_type_info_type;
119 push_namespace (std_identifier);
121 = xref_tag (class_type, get_identifier ("type_info"),
122 /*attributes=*/NULL_TREE, 1);
124 const_type_info_type = build_qualified_type (type_info_type_node,
126 type_info_ptr_type = build_pointer_type (const_type_info_type);
127 type_info_ref_type = build_reference_type (const_type_info_type);
129 VARRAY_TREE_INIT (unemitted_tinfo_decls, 10, "RTTI decls");
131 create_tinfo_types ();
134 /* Given the expression EXP of type `class *', return the head of the
135 object pointed to by EXP with type cv void*, if the class has any
136 virtual functions (TYPE_POLYMORPHIC_P), else just return the
140 build_headof (tree exp)
142 tree type = TREE_TYPE (exp);
146 my_friendly_assert (TREE_CODE (type) == POINTER_TYPE, 20000112);
147 type = TREE_TYPE (type);
149 if (!TYPE_POLYMORPHIC_P (type))
152 /* We use this a couple of times below, protect it. */
153 exp = save_expr (exp);
155 /* The offset-to-top field is at index -2 from the vptr. */
156 index = build_int_2 (-2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE, -1);
158 offset = build_vtbl_ref (build_indirect_ref (exp, NULL), index);
160 type = build_qualified_type (ptr_type_node,
161 cp_type_quals (TREE_TYPE (exp)));
162 return build (PLUS_EXPR, type, exp,
163 cp_convert (ptrdiff_type_node, offset));
166 /* Get a bad_cast node for the program to throw...
168 See libstdc++/exception.cc for __throw_bad_cast */
171 throw_bad_cast (void)
173 tree fn = get_identifier ("__cxa_bad_cast");
174 if (IDENTIFIER_GLOBAL_VALUE (fn))
175 fn = IDENTIFIER_GLOBAL_VALUE (fn);
177 fn = push_throw_library_fn (fn, build_function_type (ptr_type_node,
180 return build_cxx_call (fn, NULL_TREE, NULL_TREE);
183 /* Return an expression for "__cxa_bad_typeid()". The expression
184 returned is an lvalue of type "const std::type_info". */
187 throw_bad_typeid (void)
189 tree fn = get_identifier ("__cxa_bad_typeid");
190 if (IDENTIFIER_GLOBAL_VALUE (fn))
191 fn = IDENTIFIER_GLOBAL_VALUE (fn);
194 tree t = build_qualified_type (type_info_type_node, TYPE_QUAL_CONST);
195 t = build_function_type (build_reference_type (t), void_list_node);
196 fn = push_throw_library_fn (fn, t);
199 return convert_from_reference (build_cxx_call (fn, NULL_TREE, NULL_TREE));
202 /* Return an lvalue expression whose type is "const std::type_info"
203 and whose value indicates the type of the expression EXP. If EXP
204 is a reference to a polymorphic class, return the dynamic type;
205 otherwise return the static type of the expression. */
208 get_tinfo_decl_dynamic (tree exp)
213 if (exp == error_mark_node)
214 return error_mark_node;
216 type = TREE_TYPE (exp);
218 /* peel back references, so they match. */
219 if (TREE_CODE (type) == REFERENCE_TYPE)
220 type = TREE_TYPE (type);
222 /* Peel off cv qualifiers. */
223 type = TYPE_MAIN_VARIANT (type);
225 if (!VOID_TYPE_P (type))
226 type = complete_type_or_else (type, exp);
229 return error_mark_node;
231 /* If exp is a reference to polymorphic type, get the real type_info. */
232 if (TYPE_POLYMORPHIC_P (type) && ! resolves_to_fixed_type_p (exp, 0))
234 /* build reference to type_info from vtable. */
237 /* The RTTI information is at index -1. */
238 index = build_int_2 (-1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE, -1);
239 t = build_vtbl_ref (exp, index);
240 TREE_TYPE (t) = type_info_ptr_type;
243 /* Otherwise return the type_info for the static type of the expr. */
244 t = get_tinfo_ptr (TYPE_MAIN_VARIANT (type));
246 return build_indirect_ref (t, NULL);
254 error ("cannot use typeid with -fno-rtti");
258 if (!COMPLETE_TYPE_P (type_info_type_node))
260 error ("must #include <typeinfo> before using typeid");
267 /* Return an expression for "typeid(EXP)". The expression returned is
268 an lvalue of type "const std::type_info". */
271 build_typeid (tree exp)
273 tree cond = NULL_TREE;
276 if (exp == error_mark_node || !typeid_ok_p ())
277 return error_mark_node;
279 if (processing_template_decl)
280 return build_min (TYPEID_EXPR, type_info_ref_type, exp);
282 if (TREE_CODE (exp) == INDIRECT_REF
283 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == POINTER_TYPE
284 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp))
285 && ! resolves_to_fixed_type_p (exp, &nonnull)
288 exp = stabilize_reference (exp);
289 cond = cp_convert (boolean_type_node, TREE_OPERAND (exp, 0));
292 exp = get_tinfo_decl_dynamic (exp);
294 if (exp == error_mark_node)
295 return error_mark_node;
299 tree bad = throw_bad_typeid ();
301 exp = build (COND_EXPR, TREE_TYPE (exp), cond, exp, bad);
307 /* Generate the NTBS name of a type. */
309 tinfo_name (tree type)
314 name = mangle_type_string (type);
315 name_string = fix_string_type (build_string (strlen (name) + 1, name));
319 /* Return a VAR_DECL for the internal ABI defined type_info object for
320 TYPE. You must arrange that the decl is mark_used, if actually use
321 it --- decls in vtables are only used if the vtable is output. */
324 get_tinfo_decl (tree type)
329 if (COMPLETE_TYPE_P (type)
330 && TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
332 error ("cannot create type information for type `%T' because its size is variable",
334 return error_mark_node;
337 if (TREE_CODE (type) == OFFSET_TYPE)
338 type = TREE_TYPE (type);
339 if (TREE_CODE (type) == METHOD_TYPE)
340 type = build_function_type (TREE_TYPE (type),
341 TREE_CHAIN (TYPE_ARG_TYPES (type)));
343 /* For a class type, the variable is cached in the type node
345 if (CLASS_TYPE_P (type))
347 d = CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type));
352 name = mangle_typeinfo_for_type (type);
354 d = IDENTIFIER_GLOBAL_VALUE (name);
357 tree var_desc = get_pseudo_ti_desc (type);
359 d = build_lang_decl (VAR_DECL, name, TINFO_PSEUDO_TYPE (var_desc));
361 DECL_ARTIFICIAL (d) = 1;
362 TREE_READONLY (d) = 1;
364 DECL_EXTERNAL (d) = 1;
365 SET_DECL_ASSEMBLER_NAME (d, name);
368 pushdecl_top_level_and_finish (d, NULL_TREE);
370 if (CLASS_TYPE_P (type))
371 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type)) = d;
373 /* Remember the type it is for. */
374 TREE_TYPE (name) = type;
376 /* Add decl to the global array of tinfo decls. */
377 my_friendly_assert (unemitted_tinfo_decls != 0, 20030312);
378 VARRAY_PUSH_TREE (unemitted_tinfo_decls, d);
384 /* Return a pointer to a type_info object describing TYPE, suitably
385 cast to the language defined type. */
388 get_tinfo_ptr (tree type)
390 tree decl = get_tinfo_decl (type);
393 return build_nop (type_info_ptr_type,
394 build_address (decl));
397 /* Return the type_info object for TYPE. */
400 get_typeid (tree type)
402 if (type == error_mark_node || !typeid_ok_p ())
403 return error_mark_node;
405 if (processing_template_decl)
406 return build_min (TYPEID_EXPR, type_info_ref_type, type);
408 /* If the type of the type-id is a reference type, the result of the
409 typeid expression refers to a type_info object representing the
411 if (TREE_CODE (type) == REFERENCE_TYPE)
412 type = TREE_TYPE (type);
414 /* The top-level cv-qualifiers of the lvalue expression or the type-id
415 that is the operand of typeid are always ignored. */
416 type = TYPE_MAIN_VARIANT (type);
418 if (!VOID_TYPE_P (type))
419 type = complete_type_or_else (type, NULL_TREE);
422 return error_mark_node;
424 return build_indirect_ref (get_tinfo_ptr (type), NULL);
427 /* Check whether TEST is null before returning RESULT. If TEST is used in
428 RESULT, it must have previously had a save_expr applied to it. */
431 ifnonnull (tree test, tree result)
433 return build (COND_EXPR, TREE_TYPE (result),
434 build (EQ_EXPR, boolean_type_node, test, integer_zero_node),
435 cp_convert (TREE_TYPE (result), integer_zero_node),
439 /* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
443 build_dynamic_cast_1 (tree type, tree expr)
445 enum tree_code tc = TREE_CODE (type);
446 tree exprtype = TREE_TYPE (expr);
448 tree old_expr = expr;
449 const char *errstr = NULL;
451 /* T shall be a pointer or reference to a complete class type, or
452 `pointer to cv void''. */
456 if (TREE_CODE (TREE_TYPE (type)) == VOID_TYPE)
459 if (! IS_AGGR_TYPE (TREE_TYPE (type)))
461 errstr = "target is not pointer or reference to class";
464 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type))))
466 errstr = "target is not pointer or reference to complete type";
472 errstr = "target is not pointer or reference";
476 if (tc == POINTER_TYPE)
477 expr = convert_from_reference (expr);
478 else if (TREE_CODE (exprtype) != REFERENCE_TYPE)
480 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
481 exprtype = build_reference_type (exprtype);
482 expr = convert_to_reference (exprtype, expr, CONV_IMPLICIT,
483 LOOKUP_NORMAL, NULL_TREE);
486 exprtype = TREE_TYPE (expr);
488 if (tc == POINTER_TYPE)
490 /* If T is a pointer type, v shall be an rvalue of a pointer to
491 complete class type, and the result is an rvalue of type T. */
493 if (TREE_CODE (exprtype) != POINTER_TYPE)
495 errstr = "source is not a pointer";
498 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
500 errstr = "source is not a pointer to class";
503 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
505 errstr = "source is a pointer to incomplete type";
511 /* T is a reference type, v shall be an lvalue of a complete class
512 type, and the result is an lvalue of the type referred to by T. */
514 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
516 errstr = "source is not of class type";
519 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
521 errstr = "source is of incomplete class type";
527 /* The dynamic_cast operator shall not cast away constness. */
528 if (!at_least_as_qualified_p (TREE_TYPE (type),
529 TREE_TYPE (exprtype)))
531 errstr = "conversion casts away constness";
535 /* If *type is an unambiguous accessible base class of *exprtype,
536 convert statically. */
540 binfo = lookup_base (TREE_TYPE (exprtype), TREE_TYPE (type),
541 ba_not_special, NULL);
545 expr = build_base_path (PLUS_EXPR, convert_from_reference (expr),
547 if (TREE_CODE (exprtype) == POINTER_TYPE)
548 expr = non_lvalue (expr);
553 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
554 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype)))
557 /* if TYPE is `void *', return pointer to complete object. */
558 if (tc == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (type)))
560 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
561 if (TREE_CODE (expr) == ADDR_EXPR
562 && TREE_CODE (TREE_OPERAND (expr, 0)) == VAR_DECL
563 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE)
564 return build1 (NOP_EXPR, type, expr);
566 /* Since expr is used twice below, save it. */
567 expr = save_expr (expr);
569 expr1 = build_headof (expr);
570 if (TREE_TYPE (expr1) != type)
571 expr1 = build1 (NOP_EXPR, type, expr1);
572 return ifnonnull (expr, expr1);
577 tree result, td2, td3, elems;
578 tree static_type, target_type, boff;
580 /* If we got here, we can't convert statically. Therefore,
581 dynamic_cast<D&>(b) (b an object) cannot succeed. */
582 if (tc == REFERENCE_TYPE)
584 if (TREE_CODE (old_expr) == VAR_DECL
585 && TREE_CODE (TREE_TYPE (old_expr)) == RECORD_TYPE)
587 tree expr = throw_bad_cast ();
588 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
590 /* Bash it to the expected type. */
591 TREE_TYPE (expr) = type;
595 /* Ditto for dynamic_cast<D*>(&b). */
596 else if (TREE_CODE (expr) == ADDR_EXPR)
598 tree op = TREE_OPERAND (expr, 0);
599 if (TREE_CODE (op) == VAR_DECL
600 && TREE_CODE (TREE_TYPE (op)) == RECORD_TYPE)
602 warning ("dynamic_cast of `%#D' to `%#T' can never succeed",
604 retval = build_int_2 (0, 0);
605 TREE_TYPE (retval) = type;
610 target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
611 static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
612 td2 = get_tinfo_decl (target_type);
614 td2 = build_unary_op (ADDR_EXPR, td2, 0);
615 td3 = get_tinfo_decl (static_type);
617 td3 = build_unary_op (ADDR_EXPR, td3, 0);
619 /* Determine how T and V are related. */
620 boff = get_dynamic_cast_base_type (static_type, target_type);
622 /* Since expr is used twice below, save it. */
623 expr = save_expr (expr);
626 if (tc == REFERENCE_TYPE)
627 expr1 = build_unary_op (ADDR_EXPR, expr1, 0);
630 (NULL_TREE, expr1, tree_cons
631 (NULL_TREE, td3, tree_cons
632 (NULL_TREE, td2, tree_cons
633 (NULL_TREE, boff, NULL_TREE))));
635 dcast_fn = dynamic_cast_node;
643 push_nested_namespace (ns);
644 tinfo_ptr = xref_tag (class_type,
645 get_identifier ("__class_type_info"),
646 /*attributes=*/NULL_TREE,
649 tinfo_ptr = build_pointer_type
650 (build_qualified_type
651 (tinfo_ptr, TYPE_QUAL_CONST));
652 name = "__dynamic_cast";
654 (NULL_TREE, const_ptr_type_node, tree_cons
655 (NULL_TREE, tinfo_ptr, tree_cons
656 (NULL_TREE, tinfo_ptr, tree_cons
657 (NULL_TREE, ptrdiff_type_node, void_list_node))));
658 tmp = build_function_type (ptr_type_node, tmp);
659 dcast_fn = build_library_fn_ptr (name, tmp);
660 pop_nested_namespace (ns);
661 dynamic_cast_node = dcast_fn;
663 result = build_cxx_call (dcast_fn, elems, elems);
665 if (tc == REFERENCE_TYPE)
667 tree bad = throw_bad_cast ();
669 result = save_expr (result);
670 return build (COND_EXPR, type, result, result, bad);
673 /* Now back to the type we want from a void*. */
674 result = cp_convert (type, result);
675 return ifnonnull (expr, result);
679 errstr = "source type is not polymorphic";
682 error ("cannot dynamic_cast `%E' (of type `%#T') to type `%#T' (%s)",
683 expr, exprtype, type, errstr);
684 return error_mark_node;
688 build_dynamic_cast (tree type, tree expr)
690 if (type == error_mark_node || expr == error_mark_node)
691 return error_mark_node;
693 if (processing_template_decl)
694 return build_min (DYNAMIC_CAST_EXPR, type, expr);
696 return convert_from_reference (build_dynamic_cast_1 (type, expr));
699 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
702 qualifier_flags (tree type)
705 int quals = cp_type_quals (type);
707 if (quals & TYPE_QUAL_CONST)
709 if (quals & TYPE_QUAL_VOLATILE)
711 if (quals & TYPE_QUAL_RESTRICT)
716 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
717 contains a pointer to member of an incomplete class. */
720 target_incomplete_p (tree type)
722 while (TREE_CODE (type) == POINTER_TYPE)
723 if (TYPE_PTRMEM_P (type))
725 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type)))
727 type = TYPE_PTRMEM_POINTED_TO_TYPE (type);
730 type = TREE_TYPE (type);
731 if (!COMPLETE_OR_VOID_TYPE_P (type))
737 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
738 is the vtable pointer and NTBS name. The NTBS name is emitted as a
739 comdat const char array, so it becomes a unique key for the type. Generate
740 and emit that VAR_DECL here. (We can't always emit the type_info itself
741 as comdat, because of pointers to incomplete.) */
744 tinfo_base_init (tree desc, tree target)
746 tree init = NULL_TREE;
753 /* Generate the NTBS array variable. */
754 tree name_type = build_cplus_array_type
755 (build_qualified_type (char_type_node, TYPE_QUAL_CONST),
757 tree name_string = tinfo_name (target);
759 name_name = mangle_typeinfo_string_for_type (target);
760 name_decl = build_lang_decl (VAR_DECL, name_name, name_type);
762 DECL_ARTIFICIAL (name_decl) = 1;
763 TREE_READONLY (name_decl) = 1;
764 TREE_STATIC (name_decl) = 1;
765 DECL_EXTERNAL (name_decl) = 0;
766 TREE_PUBLIC (name_decl) = 1;
767 comdat_linkage (name_decl);
768 /* External name of the string containing the type's name has a
770 SET_DECL_ASSEMBLER_NAME (name_decl,
771 mangle_typeinfo_string_for_type (target));
772 DECL_INITIAL (name_decl) = name_string;
773 mark_used (name_decl);
774 pushdecl_top_level_and_finish (name_decl, name_string);
777 vtable_ptr = TINFO_VTABLE_DECL (desc);
782 push_nested_namespace (abi_node);
783 real_type = xref_tag (class_type, TINFO_REAL_NAME (desc),
784 /*attributes=*/NULL_TREE, 1);
785 pop_nested_namespace (abi_node);
787 if (!COMPLETE_TYPE_P (real_type))
789 /* We never saw a definition of this type, so we need to
790 tell the compiler that this is an exported class, as
791 indeed all of the __*_type_info classes are. */
792 SET_CLASSTYPE_INTERFACE_KNOWN (real_type);
793 CLASSTYPE_INTERFACE_ONLY (real_type) = 1;
796 vtable_ptr = get_vtable_decl (real_type, /*complete=*/1);
797 vtable_ptr = build_unary_op (ADDR_EXPR, vtable_ptr, 0);
799 /* We need to point into the middle of the vtable. */
801 (PLUS_EXPR, TREE_TYPE (vtable_ptr), vtable_ptr,
802 size_binop (MULT_EXPR,
803 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE),
804 TYPE_SIZE_UNIT (vtable_entry_type)));
805 TREE_CONSTANT (vtable_ptr) = 1;
807 TINFO_VTABLE_DECL (desc) = vtable_ptr;
810 init = tree_cons (NULL_TREE, vtable_ptr, init);
812 init = tree_cons (NULL_TREE, decay_conversion (name_decl), init);
814 init = build_constructor (NULL_TREE, nreverse (init));
815 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
816 init = tree_cons (NULL_TREE, init, NULL_TREE);
821 /* Return the CONSTRUCTOR expr for a type_info of TYPE. DESC provides the
822 information about the particular type_info derivation, which adds no
823 additional fields to the type_info base. */
826 generic_initializer (tree desc, tree target)
828 tree init = tinfo_base_init (desc, target);
830 init = build_constructor (NULL_TREE, init);
831 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
835 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
836 DESC provides information about the particular type_info derivation,
837 which adds target type and qualifier flags members to the type_info base. */
840 ptr_initializer (tree desc, tree target, bool *non_public_ptr)
842 tree init = tinfo_base_init (desc, target);
843 tree to = TREE_TYPE (target);
844 int flags = qualifier_flags (to);
845 bool incomplete = target_incomplete_p (to);
850 *non_public_ptr = true;
852 init = tree_cons (NULL_TREE, build_int_2 (flags, 0), init);
853 init = tree_cons (NULL_TREE,
854 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
857 init = build_constructor (NULL_TREE, nreverse (init));
858 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
862 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
863 DESC provides information about the particular type_info derivation,
864 which adds class, target type and qualifier flags members to the type_info
868 ptm_initializer (tree desc, tree target, bool *non_public_ptr)
870 tree init = tinfo_base_init (desc, target);
871 tree to = TYPE_PTRMEM_POINTED_TO_TYPE (target);
872 tree klass = TYPE_PTRMEM_CLASS_TYPE (target);
873 int flags = qualifier_flags (to);
874 bool incomplete = target_incomplete_p (to);
879 *non_public_ptr = true;
881 if (!COMPLETE_TYPE_P (klass))
884 *non_public_ptr = true;
886 init = tree_cons (NULL_TREE, build_int_2 (flags, 0), init);
887 init = tree_cons (NULL_TREE,
888 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
890 init = tree_cons (NULL_TREE,
891 get_tinfo_ptr (klass),
894 init = build_constructor (NULL_TREE, nreverse (init));
895 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
899 /* Check base BINFO to set hint flags in *DATA, which is really an int.
900 We use CLASSTYPE_MARKED to tag types we've found as non-virtual bases and
901 CLASSTYPE_MARKED2 to tag those which are virtual bases. Remember it is
902 possible for a type to be both a virtual and non-virtual base. */
905 dfs_class_hint_mark (tree binfo, void *data)
907 tree basetype = BINFO_TYPE (binfo);
908 int *hint = (int *) data;
910 if (TREE_VIA_VIRTUAL (binfo))
912 if (CLASSTYPE_MARKED (basetype))
914 if (CLASSTYPE_MARKED2 (basetype))
916 SET_CLASSTYPE_MARKED2 (basetype);
920 if (CLASSTYPE_MARKED (basetype) || CLASSTYPE_MARKED2 (basetype))
922 SET_CLASSTYPE_MARKED (basetype);
927 /* Clear the base's dfs marks, after searching for duplicate bases. */
930 dfs_class_hint_unmark (tree binfo, void *data ATTRIBUTE_UNUSED)
932 tree basetype = BINFO_TYPE (binfo);
934 CLEAR_CLASSTYPE_MARKED (basetype);
935 CLEAR_CLASSTYPE_MARKED2 (basetype);
939 /* Determine the hint flags describing the features of a class's hierarchy. */
942 class_hint_flags (tree type)
946 dfs_walk (TYPE_BINFO (type), dfs_class_hint_mark, NULL, &hint_flags);
947 dfs_walk (TYPE_BINFO (type), dfs_class_hint_unmark, NULL, NULL);
952 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
953 DESC provides information about the particular __class_type_info derivation,
954 which adds hint flags and TRAIL initializers to the type_info base. */
957 class_initializer (tree desc, tree target, tree trail)
959 tree init = tinfo_base_init (desc, target);
961 TREE_CHAIN (init) = trail;
962 init = build_constructor (NULL_TREE, init);
963 TREE_HAS_CONSTRUCTOR (init) = TREE_CONSTANT (init) = TREE_STATIC (init) = 1;
967 /* Returns true if the typeinfo for type should be placed in
968 the runtime library. */
971 typeinfo_in_lib_p (tree type)
973 /* The typeinfo objects for `T*' and `const T*' are in the runtime
974 library for simple types T. */
975 if (TREE_CODE (type) == POINTER_TYPE
976 && (cp_type_quals (TREE_TYPE (type)) == TYPE_QUAL_CONST
977 || cp_type_quals (TREE_TYPE (type)) == TYPE_UNQUALIFIED))
978 type = TREE_TYPE (type);
980 switch (TREE_CODE (type))
994 /* Generate the initializer for the type info describing
995 TYPE. VAR_DESC is a . NON_PUBLIC_P is set nonzero, if the VAR_DECL
996 should not be exported from this object file. This should only be
997 called at the end of translation, when we know that no further
998 types will be completed. */
1001 get_pseudo_ti_init (tree type, tree var_desc, bool *non_public_p)
1003 my_friendly_assert (at_eof, 20021120);
1004 switch (TREE_CODE (type))
1007 if (TYPE_PTRMEM_P (type))
1008 return ptm_initializer (var_desc, type, non_public_p);
1010 return ptr_initializer (var_desc, type, non_public_p);
1013 return generic_initializer (var_desc, type);
1016 return generic_initializer (var_desc, type);
1019 return generic_initializer (var_desc, type);
1023 if (TYPE_PTRMEMFUNC_P (type))
1024 return ptm_initializer (var_desc, type, non_public_p);
1025 else if (var_desc == class_desc_type_node)
1027 if (!COMPLETE_TYPE_P (type))
1028 /* Emit a non-public class_type_info. */
1029 *non_public_p = true;
1030 return class_initializer (var_desc, type, NULL_TREE);
1032 else if (var_desc == si_class_desc_type_node)
1034 tree base_binfos = BINFO_BASETYPES (TYPE_BINFO (type));
1035 tree base_binfo = TREE_VEC_ELT (base_binfos, 0);
1036 tree tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1037 tree base_inits = tree_cons (NULL_TREE, tinfo, NULL_TREE);
1039 return class_initializer (var_desc, type, base_inits);
1043 int hint = class_hint_flags (type);
1044 tree binfo = TYPE_BINFO (type);
1045 int nbases = BINFO_N_BASETYPES (binfo);
1046 tree base_binfos = BINFO_BASETYPES (binfo);
1047 tree base_accesses = BINFO_BASEACCESSES (binfo);
1048 tree base_inits = NULL_TREE;
1051 /* Generate the base information initializer. */
1052 for (ix = nbases; ix--;)
1054 tree base_binfo = TREE_VEC_ELT (base_binfos, ix);
1055 tree base_init = NULL_TREE;
1060 if (TREE_VEC_ELT (base_accesses, ix) == access_public_node)
1062 tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1063 if (TREE_VIA_VIRTUAL (base_binfo))
1065 /* We store the vtable offset at which the virtual
1066 base offset can be found. */
1067 offset = BINFO_VPTR_FIELD (base_binfo);
1068 offset = convert (sizetype, offset);
1072 offset = BINFO_OFFSET (base_binfo);
1074 /* combine offset and flags into one field */
1075 offset = cp_build_binary_op (LSHIFT_EXPR, offset,
1076 build_int_2 (8, 0));
1077 offset = cp_build_binary_op (BIT_IOR_EXPR, offset,
1078 build_int_2 (flags, 0));
1079 base_init = tree_cons (NULL_TREE, offset, base_init);
1080 base_init = tree_cons (NULL_TREE, tinfo, base_init);
1081 base_init = build_constructor (NULL_TREE, base_init);
1082 TREE_HAS_CONSTRUCTOR (base_init) = 1;
1083 base_inits = tree_cons (NULL_TREE, base_init, base_inits);
1085 base_inits = build_constructor (NULL_TREE, base_inits);
1086 TREE_HAS_CONSTRUCTOR (base_inits) = 1;
1087 base_inits = tree_cons (NULL_TREE, base_inits, NULL_TREE);
1088 /* Prepend the number of bases. */
1089 base_inits = tree_cons (NULL_TREE,
1090 build_int_2 (nbases, 0), base_inits);
1091 /* Prepend the hint flags. */
1092 base_inits = tree_cons (NULL_TREE,
1093 build_int_2 (hint, 0), base_inits);
1095 return class_initializer (var_desc, type, base_inits);
1100 return generic_initializer (var_desc, type);
1104 /* Generate the RECORD_TYPE containing the data layout of a type_info
1105 derivative as used by the runtime. This layout must be consistent with
1106 that defined in the runtime support. Also generate the VAR_DECL for the
1107 type's vtable. We explicitly manage the vtable member, and name it for
1108 real type as used in the runtime. The RECORD type has a different name,
1109 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1110 is the generated type and TINFO_VTABLE_NAME is the name of the
1111 vtable. We have to delay generating the VAR_DECL of the vtable
1112 until the end of the translation, when we'll have seen the library
1113 definition, if there was one.
1115 REAL_NAME is the runtime's name of the type. Trailing arguments are
1116 additional FIELD_DECL's for the structure. The final argument must be
1120 create_pseudo_type_info (const char *real_name, int ident, ...)
1129 va_start (ap, ident);
1131 /* Generate the pseudo type name. */
1132 pseudo_name = (char *)alloca (strlen (real_name) + 30);
1133 strcpy (pseudo_name, real_name);
1134 strcat (pseudo_name, "_pseudo");
1136 sprintf (pseudo_name + strlen (pseudo_name), "%d", ident);
1138 /* First field is the pseudo type_info base class. */
1139 fields = build_decl (FIELD_DECL, NULL_TREE, ti_desc_type_node);
1141 /* Now add the derived fields. */
1142 while ((field_decl = va_arg (ap, tree)))
1144 TREE_CHAIN (field_decl) = fields;
1145 fields = field_decl;
1148 /* Create the pseudo type. */
1149 pseudo_type = make_aggr_type (RECORD_TYPE);
1150 finish_builtin_struct (pseudo_type, pseudo_name, fields, NULL_TREE);
1151 CLASSTYPE_AS_BASE (pseudo_type) = pseudo_type;
1153 result = tree_cons (NULL_TREE, NULL_TREE, NULL_TREE);
1154 TINFO_REAL_NAME (result) = get_identifier (real_name);
1155 TINFO_PSEUDO_TYPE (result) =
1156 cp_build_qualified_type (pseudo_type, TYPE_QUAL_CONST);
1162 /* Return a pseudo type info type node used to describe TYPE. TYPE
1163 must be a complete type (or cv void), except at the end of the
1164 translation unit. */
1167 get_pseudo_ti_desc (tree type)
1169 switch (TREE_CODE (type))
1172 return TYPE_PTRMEM_P (type) ? ptm_desc_type_node : ptr_desc_type_node;
1174 return enum_desc_type_node;
1176 return func_desc_type_node;
1178 return ary_desc_type_node;
1181 if (TYPE_PTRMEMFUNC_P (type))
1182 return ptm_desc_type_node;
1183 else if (!COMPLETE_TYPE_P (type))
1186 cxx_incomplete_type_error (NULL_TREE, type);
1187 return class_desc_type_node;
1189 else if (!CLASSTYPE_N_BASECLASSES (type))
1190 return class_desc_type_node;
1193 tree binfo = TYPE_BINFO (type);
1194 tree base_binfos = BINFO_BASETYPES (binfo);
1195 tree base_accesses = BINFO_BASEACCESSES (binfo);
1196 tree base_binfo = TREE_VEC_ELT (base_binfos, 0);
1197 int num_bases = TREE_VEC_LENGTH (base_binfos);
1200 && TREE_VEC_ELT (base_accesses, 0) == access_public_node
1201 && !TREE_VIA_VIRTUAL (base_binfo)
1202 && integer_zerop (BINFO_OFFSET (base_binfo)))
1203 /* single non-virtual public. */
1204 return si_class_desc_type_node;
1208 tree array_domain, base_array;
1210 if (TREE_VEC_LENGTH (vmi_class_desc_type_node) <= num_bases)
1213 tree extend = make_tree_vec (num_bases + 5);
1215 for (ix = TREE_VEC_LENGTH (vmi_class_desc_type_node); ix--;)
1216 TREE_VEC_ELT (extend, ix)
1217 = TREE_VEC_ELT (vmi_class_desc_type_node, ix);
1218 vmi_class_desc_type_node = extend;
1220 var_desc = TREE_VEC_ELT (vmi_class_desc_type_node, num_bases);
1224 /* Create the array of __base_class_type_info entries.
1225 G++ 3.2 allocated an array that had one too many
1226 entries, and then filled that extra entries with
1228 if (abi_version_at_least (2))
1229 array_domain = build_index_type (size_int (num_bases - 1));
1231 array_domain = build_index_type (size_int (num_bases));
1233 build_array_type (base_desc_type_node, array_domain);
1235 push_nested_namespace (abi_node);
1236 var_desc = create_pseudo_type_info
1237 ("__vmi_class_type_info", num_bases,
1238 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1239 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1240 build_decl (FIELD_DECL, NULL_TREE, base_array),
1242 pop_nested_namespace (abi_node);
1244 TREE_VEC_ELT (vmi_class_desc_type_node, num_bases) = var_desc;
1249 return bltn_desc_type_node;
1253 /* Make sure the required builtin types exist for generating the type_info
1254 varable definitions. */
1257 create_tinfo_types (void)
1259 my_friendly_assert (!ti_desc_type_node, 20020609);
1261 push_nested_namespace (abi_node);
1263 /* Create the internal type_info structure. This is used as a base for
1264 the other structures. */
1268 ti_desc_type_node = make_aggr_type (RECORD_TYPE);
1269 field = build_decl (FIELD_DECL, NULL_TREE, const_ptr_type_node);
1272 field = build_decl (FIELD_DECL, NULL_TREE, const_string_type_node);
1273 TREE_CHAIN (field) = fields;
1276 finish_builtin_struct (ti_desc_type_node, "__type_info_pseudo",
1278 TYPE_HAS_CONSTRUCTOR (ti_desc_type_node) = 1;
1281 /* Fundamental type_info */
1282 bltn_desc_type_node = create_pseudo_type_info
1283 ("__fundamental_type_info", 0,
1286 /* Array, function and enum type_info. No additional fields. */
1287 ary_desc_type_node = create_pseudo_type_info
1288 ("__array_type_info", 0,
1290 func_desc_type_node = create_pseudo_type_info
1291 ("__function_type_info", 0,
1293 enum_desc_type_node = create_pseudo_type_info
1294 ("__enum_type_info", 0,
1297 /* Class type_info. Add a flags field. */
1298 class_desc_type_node = create_pseudo_type_info
1299 ("__class_type_info", 0,
1302 /* Single public non-virtual base class. Add pointer to base class.
1303 This is really a descendant of __class_type_info. */
1304 si_class_desc_type_node = create_pseudo_type_info
1305 ("__si_class_type_info", 0,
1306 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1309 /* Base class internal helper. Pointer to base type, offset to base,
1314 field = build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type);
1317 field = build_decl (FIELD_DECL, NULL_TREE, integer_types[itk_long]);
1318 TREE_CHAIN (field) = fields;
1321 base_desc_type_node = make_aggr_type (RECORD_TYPE);
1322 finish_builtin_struct (base_desc_type_node, "__base_class_type_info_pseudo",
1324 TYPE_HAS_CONSTRUCTOR (base_desc_type_node) = 1;
1327 /* General hierarchy is created as necessary in this vector. */
1328 vmi_class_desc_type_node = make_tree_vec (10);
1330 /* Pointer type_info. Adds two fields, qualification mask
1331 and pointer to the pointed to type. This is really a descendant of
1332 __pbase_type_info. */
1333 ptr_desc_type_node = create_pseudo_type_info
1334 ("__pointer_type_info", 0,
1335 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1336 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1339 /* Pointer to member data type_info. Add qualifications flags,
1340 pointer to the member's type info and pointer to the class.
1341 This is really a descendant of __pbase_type_info. */
1342 ptm_desc_type_node = create_pseudo_type_info
1343 ("__pointer_to_member_type_info", 0,
1344 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1345 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1346 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1349 pop_nested_namespace (abi_node);
1352 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1353 support. Generating them here guarantees consistency with the other
1354 structures. We use the following heuristic to determine when the runtime
1355 is being generated. If std::__fundamental_type_info is defined, and its
1356 destructor is defined, then the runtime is being built. */
1359 emit_support_tinfos (void)
1361 static tree *const fundamentals[] =
1366 &char_type_node, &signed_char_type_node, &unsigned_char_type_node,
1367 &short_integer_type_node, &short_unsigned_type_node,
1368 &integer_type_node, &unsigned_type_node,
1369 &long_integer_type_node, &long_unsigned_type_node,
1370 &long_long_integer_type_node, &long_long_unsigned_type_node,
1371 &float_type_node, &double_type_node, &long_double_type_node,
1375 tree bltn_type, dtor;
1377 push_nested_namespace (abi_node);
1378 bltn_type = xref_tag (class_type,
1379 get_identifier ("__fundamental_type_info"),
1380 /*attributes=*/NULL_TREE,
1382 pop_nested_namespace (abi_node);
1383 if (!COMPLETE_TYPE_P (bltn_type))
1385 dtor = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (bltn_type), 1);
1386 if (DECL_EXTERNAL (dtor))
1389 for (ix = 0; fundamentals[ix]; ix++)
1391 tree bltn = *fundamentals[ix];
1392 tree bltn_ptr = build_pointer_type (bltn);
1393 tree bltn_const_ptr = build_pointer_type
1394 (build_qualified_type (bltn, TYPE_QUAL_CONST));
1397 tinfo = get_tinfo_decl (bltn);
1398 TREE_USED (tinfo) = 1;
1399 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1401 tinfo = get_tinfo_decl (bltn_ptr);
1402 TREE_USED (tinfo) = 1;
1403 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1405 tinfo = get_tinfo_decl (bltn_const_ptr);
1406 TREE_USED (tinfo) = 1;
1407 TREE_SYMBOL_REFERENCED (DECL_ASSEMBLER_NAME (tinfo)) = 1;
1411 /* Return true, iff T is a type_info variable which has not had a
1412 definition emitted for it. */
1415 unemitted_tinfo_decl_p (tree t)
1417 if (/* It's a var decl */
1418 TREE_CODE (t) == VAR_DECL
1419 /* which has a name */
1421 /* whose name points back to itself */
1422 && IDENTIFIER_GLOBAL_VALUE (DECL_NAME (t)) == t
1423 /* whose name's type is non-null */
1424 && TREE_TYPE (DECL_NAME (t))
1425 /* and whose type is a struct */
1426 && TREE_CODE (TREE_TYPE (t)) == RECORD_TYPE
1428 && TYPE_FIELDS (TREE_TYPE (t))
1429 /* which is our pseudo type info */
1430 && TREE_TYPE (TYPE_FIELDS (TREE_TYPE (t))) == ti_desc_type_node)
1435 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1436 tinfo decl. Determine whether it needs emitting, and if so
1437 generate the initializer. */
1440 emit_tinfo_decl (tree decl)
1442 tree type = TREE_TYPE (DECL_NAME (decl));
1444 int in_library = typeinfo_in_lib_p (type);
1445 tree var_desc, var_init;
1447 my_friendly_assert (unemitted_tinfo_decl_p (decl), 20030307);
1449 import_export_tinfo (decl, type, in_library);
1450 if (DECL_REALLY_EXTERN (decl) || !DECL_NEEDED_P (decl))
1453 if (!doing_runtime && in_library)
1457 var_desc = get_pseudo_ti_desc (type);
1458 var_init = get_pseudo_ti_init (type, var_desc, &non_public);
1460 DECL_EXTERNAL (decl) = 0;
1461 TREE_PUBLIC (decl) = !non_public;
1463 DECL_COMDAT (decl) = 0;
1465 DECL_INITIAL (decl) = var_init;
1467 cp_finish_decl (decl, var_init, NULL_TREE, 0);
1468 /* cp_finish_decl will have dealt with linkage. */
1470 /* Say we've dealt with it. */
1471 TREE_TYPE (DECL_NAME (decl)) = NULL_TREE;