1 /* RunTime Type Identification
2 Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4 Free Software Foundation, Inc.
5 Mostly written by Jason Merrill (jason@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 2, 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 COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
26 #include "coretypes.h"
37 /* C++ returns type information to the user in struct type_info
38 objects. We also use type information to implement dynamic_cast and
39 exception handlers. Type information for a particular type is
40 indicated with an ABI defined structure derived from type_info.
41 This would all be very straight forward, but for the fact that the
42 runtime library provides the definitions of the type_info structure
43 and the ABI defined derived classes. We cannot build declarations
44 of them directly in the compiler, but we need to layout objects of
45 their type. Somewhere we have to lie.
47 We define layout compatible POD-structs with compiler-defined names
48 and generate the appropriate initializations for them (complete
49 with explicit mention of their vtable). When we have to provide a
50 type_info to the user we reinterpret_cast the internal compiler
51 type to type_info. A well formed program can only explicitly refer
52 to the type_infos of complete types (& cv void). However, we chain
53 pointer type_infos to the pointed-to-type, and that can be
54 incomplete. We only need the addresses of such incomplete
55 type_info objects for static initialization.
57 The type information VAR_DECL of a type is held on the
58 IDENTIFIER_GLOBAL_VALUE of the type's mangled name. That VAR_DECL
59 will be the internal type. It will usually have the correct
60 internal type reflecting the kind of type it represents (pointer,
61 array, function, class, inherited class, etc). When the type it
62 represents is incomplete, it will have the internal type
63 corresponding to type_info. That will only happen at the end of
64 translation, when we are emitting the type info objects. */
66 /* Auxiliary data we hold for each type_info derived object we need. */
67 typedef struct tinfo_s GTY (())
69 tree type; /* The RECORD_TYPE for this type_info object */
71 tree vtable; /* The VAR_DECL of the vtable. Only filled at end of
74 tree name; /* IDENTIFIER_NODE for the ABI specified name of
75 the type_info derived type. */
79 DEF_VEC_ALLOC_O(tinfo_s,gc);
81 typedef enum tinfo_kind
83 TK_TYPE_INFO_TYPE, /* std::type_info */
84 TK_BASE_TYPE, /* abi::__base_class_type_info */
85 TK_BUILTIN_TYPE, /* abi::__fundamental_type_info */
86 TK_ARRAY_TYPE, /* abi::__array_type_info */
87 TK_FUNCTION_TYPE, /* abi::__function_type_info */
88 TK_ENUMERAL_TYPE, /* abi::__enum_type_info */
89 TK_POINTER_TYPE, /* abi::__pointer_type_info */
90 TK_POINTER_MEMBER_TYPE, /* abi::__pointer_to_member_type_info */
91 TK_CLASS_TYPE, /* abi::__class_type_info */
92 TK_SI_CLASS_TYPE, /* abi::__si_class_type_info */
93 TK_FIXED /* end of fixed descriptors. */
94 /* ... abi::__vmi_type_info<I> */
97 /* A vector of all tinfo decls that haven't yet been emitted. */
98 VEC(tree,gc) *unemitted_tinfo_decls;
100 /* A vector of all type_info derived types we need. The first few are
101 fixed and created early. The remainder are for multiple inheritance
102 and are generated as needed. */
103 static GTY (()) VEC(tinfo_s,gc) *tinfo_descs;
105 static tree build_headof (tree);
106 static tree ifnonnull (tree, tree);
107 static tree tinfo_name (tree);
108 static tree build_dynamic_cast_1 (tree, tree);
109 static tree throw_bad_cast (void);
110 static tree throw_bad_typeid (void);
111 static tree get_tinfo_decl_dynamic (tree);
112 static tree get_tinfo_ptr (tree);
113 static bool typeid_ok_p (void);
114 static int qualifier_flags (tree);
115 static bool target_incomplete_p (tree);
116 static tree tinfo_base_init (tinfo_s *, tree);
117 static tree generic_initializer (tinfo_s *, tree);
118 static tree ptr_initializer (tinfo_s *, tree);
119 static tree ptm_initializer (tinfo_s *, tree);
120 static tree class_initializer (tinfo_s *, tree, tree);
121 static void create_pseudo_type_info (int, const char *, ...);
122 static tree get_pseudo_ti_init (tree, unsigned);
123 static unsigned get_pseudo_ti_index (tree);
124 static void create_tinfo_types (void);
125 static bool typeinfo_in_lib_p (tree);
127 static int doing_runtime = 0;
130 /* Declare language defined type_info type and a pointer to const
131 type_info. This is incomplete here, and will be completed when
132 the user #includes <typeinfo>. There are language defined
133 restrictions on what can be done until that is included. Create
134 the internal versions of the ABI types. */
137 init_rtti_processing (void)
141 push_namespace (std_identifier);
142 type_info_type = xref_tag (class_type, get_identifier ("type_info"),
143 /*tag_scope=*/ts_current, false);
145 const_type_info_type_node
146 = build_qualified_type (type_info_type, TYPE_QUAL_CONST);
147 type_info_ptr_type = build_pointer_type (const_type_info_type_node);
149 unemitted_tinfo_decls = VEC_alloc (tree, gc, 124);
151 create_tinfo_types ();
154 /* Given the expression EXP of type `class *', return the head of the
155 object pointed to by EXP with type cv void*, if the class has any
156 virtual functions (TYPE_POLYMORPHIC_P), else just return the
160 build_headof (tree exp)
162 tree type = TREE_TYPE (exp);
166 gcc_assert (TREE_CODE (type) == POINTER_TYPE);
167 type = TREE_TYPE (type);
169 if (!TYPE_POLYMORPHIC_P (type))
172 /* We use this a couple of times below, protect it. */
173 exp = save_expr (exp);
175 /* The offset-to-top field is at index -2 from the vptr. */
176 index = build_int_cst (NULL_TREE,
177 -2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
179 offset = build_vtbl_ref (build_indirect_ref (exp, NULL), index);
181 type = build_qualified_type (ptr_type_node,
182 cp_type_quals (TREE_TYPE (exp)));
183 return build2 (PLUS_EXPR, type, exp,
184 convert_to_integer (ptrdiff_type_node, offset));
187 /* Get a bad_cast node for the program to throw...
189 See libstdc++/exception.cc for __throw_bad_cast */
192 throw_bad_cast (void)
194 tree fn = get_identifier ("__cxa_bad_cast");
195 if (!get_global_value_if_present (fn, &fn))
196 fn = push_throw_library_fn (fn, build_function_type (ptr_type_node,
199 return build_cxx_call (fn, NULL_TREE);
202 /* Return an expression for "__cxa_bad_typeid()". The expression
203 returned is an lvalue of type "const std::type_info". */
206 throw_bad_typeid (void)
208 tree fn = get_identifier ("__cxa_bad_typeid");
209 if (!get_global_value_if_present (fn, &fn))
213 t = build_reference_type (const_type_info_type_node);
214 t = build_function_type (t, void_list_node);
215 fn = push_throw_library_fn (fn, t);
218 return build_cxx_call (fn, NULL_TREE);
221 /* Return an lvalue expression whose type is "const std::type_info"
222 and whose value indicates the type of the expression EXP. If EXP
223 is a reference to a polymorphic class, return the dynamic type;
224 otherwise return the static type of the expression. */
227 get_tinfo_decl_dynamic (tree exp)
232 if (error_operand_p (exp))
233 return error_mark_node;
235 /* peel back references, so they match. */
236 type = non_reference (TREE_TYPE (exp));
238 /* Peel off cv qualifiers. */
239 type = TYPE_MAIN_VARIANT (type);
241 if (CLASS_TYPE_P (type))
242 type = complete_type_or_else (type, exp);
245 return error_mark_node;
247 /* If exp is a reference to polymorphic type, get the real type_info. */
248 if (TYPE_POLYMORPHIC_P (type) && ! resolves_to_fixed_type_p (exp, 0))
250 /* build reference to type_info from vtable. */
253 /* The RTTI information is at index -1. */
254 index = build_int_cst (NULL_TREE,
255 -1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE);
256 t = build_vtbl_ref (exp, index);
257 t = convert (type_info_ptr_type, t);
260 /* Otherwise return the type_info for the static type of the expr. */
261 t = get_tinfo_ptr (TYPE_MAIN_VARIANT (type));
263 return build_indirect_ref (t, NULL);
271 error ("cannot use typeid with -fno-rtti");
275 if (!COMPLETE_TYPE_P (const_type_info_type_node))
277 error ("must #include <typeinfo> before using typeid");
284 /* Return an expression for "typeid(EXP)". The expression returned is
285 an lvalue of type "const std::type_info". */
288 build_typeid (tree exp)
290 tree cond = NULL_TREE;
293 if (exp == error_mark_node || !typeid_ok_p ())
294 return error_mark_node;
296 if (processing_template_decl)
297 return build_min (TYPEID_EXPR, const_type_info_type_node, exp);
299 if (TREE_CODE (exp) == INDIRECT_REF
300 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp, 0))) == POINTER_TYPE
301 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp))
302 && ! resolves_to_fixed_type_p (exp, &nonnull)
305 exp = stabilize_reference (exp);
306 cond = cp_convert (boolean_type_node, TREE_OPERAND (exp, 0));
309 exp = get_tinfo_decl_dynamic (exp);
311 if (exp == error_mark_node)
312 return error_mark_node;
316 tree bad = throw_bad_typeid ();
318 exp = build3 (COND_EXPR, TREE_TYPE (exp), cond, exp, bad);
324 /* Generate the NTBS name of a type. */
326 tinfo_name (tree type)
331 name = mangle_type_string (type);
332 name_string = fix_string_type (build_string (strlen (name) + 1, name));
336 /* Return a VAR_DECL for the internal ABI defined type_info object for
337 TYPE. You must arrange that the decl is mark_used, if actually use
338 it --- decls in vtables are only used if the vtable is output. */
341 get_tinfo_decl (tree type)
346 if (variably_modified_type_p (type, /*fn=*/NULL_TREE))
348 error ("cannot create type information for type %qT because "
349 "it involves types of variable size",
351 return error_mark_node;
354 if (TREE_CODE (type) == METHOD_TYPE)
355 type = build_function_type (TREE_TYPE (type),
356 TREE_CHAIN (TYPE_ARG_TYPES (type)));
358 /* For a class type, the variable is cached in the type node
360 if (CLASS_TYPE_P (type))
362 d = CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type));
367 name = mangle_typeinfo_for_type (type);
369 d = IDENTIFIER_GLOBAL_VALUE (name);
372 int ix = get_pseudo_ti_index (type);
373 tinfo_s *ti = VEC_index (tinfo_s, tinfo_descs, ix);
375 d = build_lang_decl (VAR_DECL, name, ti->type);
376 SET_DECL_ASSEMBLER_NAME (d, name);
377 /* Remember the type it is for. */
378 TREE_TYPE (name) = type;
379 DECL_TINFO_P (d) = 1;
380 DECL_ARTIFICIAL (d) = 1;
381 DECL_IGNORED_P (d) = 1;
382 TREE_READONLY (d) = 1;
384 /* Mark the variable as undefined -- but remember that we can
385 define it later if we need to do so. */
386 DECL_EXTERNAL (d) = 1;
387 DECL_NOT_REALLY_EXTERN (d) = 1;
388 if (CLASS_TYPE_P (type))
389 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type)) = d;
390 set_linkage_according_to_type (type, d);
391 pushdecl_top_level_and_finish (d, NULL_TREE);
393 /* Add decl to the global array of tinfo decls. */
394 VEC_safe_push (tree, gc, unemitted_tinfo_decls, d);
400 /* Return a pointer to a type_info object describing TYPE, suitably
401 cast to the language defined type. */
404 get_tinfo_ptr (tree type)
406 tree decl = get_tinfo_decl (type);
409 return build_nop (type_info_ptr_type,
410 build_address (decl));
413 /* Return the type_info object for TYPE. */
416 get_typeid (tree type)
418 if (type == error_mark_node || !typeid_ok_p ())
419 return error_mark_node;
421 if (processing_template_decl)
422 return build_min (TYPEID_EXPR, const_type_info_type_node, type);
424 /* If the type of the type-id is a reference type, the result of the
425 typeid expression refers to a type_info object representing the
427 type = non_reference (type);
429 /* The top-level cv-qualifiers of the lvalue expression or the type-id
430 that is the operand of typeid are always ignored. */
431 type = TYPE_MAIN_VARIANT (type);
433 if (CLASS_TYPE_P (type))
434 type = complete_type_or_else (type, NULL_TREE);
437 return error_mark_node;
439 return build_indirect_ref (get_tinfo_ptr (type), NULL);
442 /* Check whether TEST is null before returning RESULT. If TEST is used in
443 RESULT, it must have previously had a save_expr applied to it. */
446 ifnonnull (tree test, tree result)
448 return build3 (COND_EXPR, TREE_TYPE (result),
449 build2 (EQ_EXPR, boolean_type_node, test,
450 cp_convert (TREE_TYPE (test), integer_zero_node)),
451 cp_convert (TREE_TYPE (result), integer_zero_node),
455 /* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
459 build_dynamic_cast_1 (tree type, tree expr)
461 enum tree_code tc = TREE_CODE (type);
462 tree exprtype = TREE_TYPE (expr);
464 tree old_expr = expr;
465 const char *errstr = NULL;
467 /* Save casted types in the function's used types hash table. */
468 used_types_insert (type);
470 /* T shall be a pointer or reference to a complete class type, or
471 `pointer to cv void''. */
475 if (TREE_CODE (TREE_TYPE (type)) == VOID_TYPE)
479 if (! IS_AGGR_TYPE (TREE_TYPE (type)))
481 errstr = "target is not pointer or reference to class";
484 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type))))
486 errstr = "target is not pointer or reference to complete type";
492 errstr = "target is not pointer or reference";
496 if (tc == POINTER_TYPE)
498 /* If T is a pointer type, v shall be an rvalue of a pointer to
499 complete class type, and the result is an rvalue of type T. */
501 if (TREE_CODE (exprtype) != POINTER_TYPE)
503 errstr = "source is not a pointer";
506 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
508 errstr = "source is not a pointer to class";
511 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
513 errstr = "source is a pointer to incomplete type";
519 exprtype = build_reference_type (exprtype);
521 /* T is a reference type, v shall be an lvalue of a complete class
522 type, and the result is an lvalue of the type referred to by T. */
524 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype)))
526 errstr = "source is not of class type";
529 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype))))
531 errstr = "source is of incomplete class type";
535 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
536 expr = convert_to_reference (exprtype, expr, CONV_IMPLICIT,
537 LOOKUP_NORMAL, NULL_TREE);
540 /* The dynamic_cast operator shall not cast away constness. */
541 if (!at_least_as_qualified_p (TREE_TYPE (type),
542 TREE_TYPE (exprtype)))
544 errstr = "conversion casts away constness";
548 /* If *type is an unambiguous accessible base class of *exprtype,
549 convert statically. */
553 binfo = lookup_base (TREE_TYPE (exprtype), TREE_TYPE (type),
558 expr = build_base_path (PLUS_EXPR, convert_from_reference (expr),
560 if (TREE_CODE (exprtype) == POINTER_TYPE)
561 expr = rvalue (expr);
566 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
567 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype)))
570 /* if TYPE is `void *', return pointer to complete object. */
571 if (tc == POINTER_TYPE && VOID_TYPE_P (TREE_TYPE (type)))
573 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
574 if (TREE_CODE (expr) == ADDR_EXPR
575 && TREE_CODE (TREE_OPERAND (expr, 0)) == VAR_DECL
576 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == RECORD_TYPE)
577 return build1 (NOP_EXPR, type, expr);
579 /* Since expr is used twice below, save it. */
580 expr = save_expr (expr);
582 expr1 = build_headof (expr);
583 if (TREE_TYPE (expr1) != type)
584 expr1 = build1 (NOP_EXPR, type, expr1);
585 return ifnonnull (expr, expr1);
590 tree result, td2, td3, elems;
591 tree static_type, target_type, boff;
593 /* If we got here, we can't convert statically. Therefore,
594 dynamic_cast<D&>(b) (b an object) cannot succeed. */
595 if (tc == REFERENCE_TYPE)
597 if (TREE_CODE (old_expr) == VAR_DECL
598 && TREE_CODE (TREE_TYPE (old_expr)) == RECORD_TYPE)
600 tree expr = throw_bad_cast ();
601 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
603 /* Bash it to the expected type. */
604 TREE_TYPE (expr) = type;
608 /* Ditto for dynamic_cast<D*>(&b). */
609 else if (TREE_CODE (expr) == ADDR_EXPR)
611 tree op = TREE_OPERAND (expr, 0);
612 if (TREE_CODE (op) == VAR_DECL
613 && TREE_CODE (TREE_TYPE (op)) == RECORD_TYPE)
615 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
617 retval = build_int_cst (type, 0);
622 /* Use of dynamic_cast when -fno-rtti is prohibited. */
625 error ("%<dynamic_cast%> not permitted with -fno-rtti");
626 return error_mark_node;
629 target_type = TYPE_MAIN_VARIANT (TREE_TYPE (type));
630 static_type = TYPE_MAIN_VARIANT (TREE_TYPE (exprtype));
631 td2 = get_tinfo_decl (target_type);
633 td2 = build_unary_op (ADDR_EXPR, td2, 0);
634 td3 = get_tinfo_decl (static_type);
636 td3 = build_unary_op (ADDR_EXPR, td3, 0);
638 /* Determine how T and V are related. */
639 boff = dcast_base_hint (static_type, target_type);
641 /* Since expr is used twice below, save it. */
642 expr = save_expr (expr);
645 if (tc == REFERENCE_TYPE)
646 expr1 = build_unary_op (ADDR_EXPR, expr1, 0);
649 (NULL_TREE, expr1, tree_cons
650 (NULL_TREE, td3, tree_cons
651 (NULL_TREE, td2, tree_cons
652 (NULL_TREE, boff, NULL_TREE))));
654 dcast_fn = dynamic_cast_node;
662 push_nested_namespace (ns);
663 tinfo_ptr = xref_tag (class_type,
664 get_identifier ("__class_type_info"),
665 /*tag_scope=*/ts_current, false);
667 tinfo_ptr = build_pointer_type
668 (build_qualified_type
669 (tinfo_ptr, TYPE_QUAL_CONST));
670 name = "__dynamic_cast";
672 (NULL_TREE, const_ptr_type_node, tree_cons
673 (NULL_TREE, tinfo_ptr, tree_cons
674 (NULL_TREE, tinfo_ptr, tree_cons
675 (NULL_TREE, ptrdiff_type_node, void_list_node))));
676 tmp = build_function_type (ptr_type_node, tmp);
677 dcast_fn = build_library_fn_ptr (name, tmp);
678 DECL_IS_PURE (dcast_fn) = 1;
679 pop_nested_namespace (ns);
680 dynamic_cast_node = dcast_fn;
682 result = build_cxx_call (dcast_fn, elems);
684 if (tc == REFERENCE_TYPE)
686 tree bad = throw_bad_cast ();
689 result = save_expr (result);
690 neq = c_common_truthvalue_conversion (result);
691 return build3 (COND_EXPR, type, neq, result, bad);
694 /* Now back to the type we want from a void*. */
695 result = cp_convert (type, result);
696 return ifnonnull (expr, result);
700 errstr = "source type is not polymorphic";
703 error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
704 expr, exprtype, type, errstr);
705 return error_mark_node;
709 build_dynamic_cast (tree type, tree expr)
711 if (type == error_mark_node || expr == error_mark_node)
712 return error_mark_node;
714 if (processing_template_decl)
716 expr = build_min (DYNAMIC_CAST_EXPR, type, expr);
717 TREE_SIDE_EFFECTS (expr) = 1;
722 return convert_from_reference (build_dynamic_cast_1 (type, expr));
725 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
728 qualifier_flags (tree type)
731 int quals = cp_type_quals (type);
733 if (quals & TYPE_QUAL_CONST)
735 if (quals & TYPE_QUAL_VOLATILE)
737 if (quals & TYPE_QUAL_RESTRICT)
742 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
743 contains a pointer to member of an incomplete class. */
746 target_incomplete_p (tree type)
749 if (TYPE_PTRMEM_P (type))
751 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type)))
753 type = TYPE_PTRMEM_POINTED_TO_TYPE (type);
755 else if (TREE_CODE (type) == POINTER_TYPE)
756 type = TREE_TYPE (type);
758 return !COMPLETE_OR_VOID_TYPE_P (type);
761 /* Returns true if TYPE involves an incomplete class type; in that
762 case, typeinfo variables for TYPE should be emitted with internal
766 involves_incomplete_p (tree type)
768 switch (TREE_CODE (type))
771 return target_incomplete_p (TREE_TYPE (type));
776 (target_incomplete_p (TYPE_PTRMEM_POINTED_TO_TYPE (type))
777 || !COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type)));
780 if (TYPE_PTRMEMFUNC_P (type))
784 if (!COMPLETE_TYPE_P (type))
788 /* All other types do not involve incomplete class types. */
793 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
794 is the vtable pointer and NTBS name. The NTBS name is emitted as a
795 comdat const char array, so it becomes a unique key for the type. Generate
796 and emit that VAR_DECL here. (We can't always emit the type_info itself
797 as comdat, because of pointers to incomplete.) */
800 tinfo_base_init (tinfo_s *ti, tree target)
802 tree init = NULL_TREE;
809 /* Generate the NTBS array variable. */
810 tree name_type = build_cplus_array_type
811 (build_qualified_type (char_type_node, TYPE_QUAL_CONST),
813 tree name_string = tinfo_name (target);
815 /* Determine the name of the variable -- and remember with which
816 type it is associated. */
817 name_name = mangle_typeinfo_string_for_type (target);
818 TREE_TYPE (name_name) = target;
820 name_decl = build_lang_decl (VAR_DECL, name_name, name_type);
821 SET_DECL_ASSEMBLER_NAME (name_decl, name_name);
822 DECL_ARTIFICIAL (name_decl) = 1;
823 DECL_IGNORED_P (name_decl) = 1;
824 TREE_READONLY (name_decl) = 1;
825 TREE_STATIC (name_decl) = 1;
826 DECL_EXTERNAL (name_decl) = 0;
827 DECL_TINFO_P (name_decl) = 1;
828 set_linkage_according_to_type (target, name_decl);
829 import_export_decl (name_decl);
830 DECL_INITIAL (name_decl) = name_string;
831 mark_used (name_decl);
832 pushdecl_top_level_and_finish (name_decl, name_string);
835 vtable_ptr = ti->vtable;
839 push_nested_namespace (abi_node);
840 real_type = xref_tag (class_type, ti->name,
841 /*tag_scope=*/ts_current, false);
842 pop_nested_namespace (abi_node);
844 if (!COMPLETE_TYPE_P (real_type))
846 /* We never saw a definition of this type, so we need to
847 tell the compiler that this is an exported class, as
848 indeed all of the __*_type_info classes are. */
849 SET_CLASSTYPE_INTERFACE_KNOWN (real_type);
850 CLASSTYPE_INTERFACE_ONLY (real_type) = 1;
853 vtable_ptr = get_vtable_decl (real_type, /*complete=*/1);
854 vtable_ptr = build_unary_op (ADDR_EXPR, vtable_ptr, 0);
856 /* We need to point into the middle of the vtable. */
858 (PLUS_EXPR, TREE_TYPE (vtable_ptr), vtable_ptr,
859 size_binop (MULT_EXPR,
860 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE),
861 TYPE_SIZE_UNIT (vtable_entry_type)));
863 ti->vtable = vtable_ptr;
866 init = tree_cons (NULL_TREE, vtable_ptr, init);
868 init = tree_cons (NULL_TREE, decay_conversion (name_decl), init);
870 init = build_constructor_from_list (NULL_TREE, nreverse (init));
871 TREE_CONSTANT (init) = 1;
872 TREE_INVARIANT (init) = 1;
873 TREE_STATIC (init) = 1;
874 init = tree_cons (NULL_TREE, init, NULL_TREE);
879 /* Return the CONSTRUCTOR expr for a type_info of TYPE. TI provides the
880 information about the particular type_info derivation, which adds no
881 additional fields to the type_info base. */
884 generic_initializer (tinfo_s *ti, tree target)
886 tree init = tinfo_base_init (ti, target);
888 init = build_constructor_from_list (NULL_TREE, init);
889 TREE_CONSTANT (init) = 1;
890 TREE_INVARIANT (init) = 1;
891 TREE_STATIC (init) = 1;
895 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
896 TI provides information about the particular type_info derivation,
897 which adds target type and qualifier flags members to the type_info base. */
900 ptr_initializer (tinfo_s *ti, tree target)
902 tree init = tinfo_base_init (ti, target);
903 tree to = TREE_TYPE (target);
904 int flags = qualifier_flags (to);
905 bool incomplete = target_incomplete_p (to);
909 init = tree_cons (NULL_TREE, build_int_cst (NULL_TREE, flags), init);
910 init = tree_cons (NULL_TREE,
911 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
914 init = build_constructor_from_list (NULL_TREE, nreverse (init));
915 TREE_CONSTANT (init) = 1;
916 TREE_INVARIANT (init) = 1;
917 TREE_STATIC (init) = 1;
921 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
922 TI provides information about the particular type_info derivation,
923 which adds class, target type and qualifier flags members to the type_info
927 ptm_initializer (tinfo_s *ti, tree target)
929 tree init = tinfo_base_init (ti, target);
930 tree to = TYPE_PTRMEM_POINTED_TO_TYPE (target);
931 tree klass = TYPE_PTRMEM_CLASS_TYPE (target);
932 int flags = qualifier_flags (to);
933 bool incomplete = target_incomplete_p (to);
937 if (!COMPLETE_TYPE_P (klass))
939 init = tree_cons (NULL_TREE, build_int_cst (NULL_TREE, flags), init);
940 init = tree_cons (NULL_TREE,
941 get_tinfo_ptr (TYPE_MAIN_VARIANT (to)),
943 init = tree_cons (NULL_TREE,
944 get_tinfo_ptr (klass),
947 init = build_constructor_from_list (NULL_TREE, nreverse (init));
948 TREE_CONSTANT (init) = 1;
949 TREE_INVARIANT (init) = 1;
950 TREE_STATIC (init) = 1;
954 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
955 TI provides information about the particular __class_type_info derivation,
956 which adds hint flags and TRAIL initializers to the type_info base. */
959 class_initializer (tinfo_s *ti, tree target, tree trail)
961 tree init = tinfo_base_init (ti, target);
963 TREE_CHAIN (init) = trail;
964 init = build_constructor_from_list (NULL_TREE, init);
965 TREE_CONSTANT (init) = 1;
966 TREE_INVARIANT (init) = 1;
967 TREE_STATIC (init) = 1;
971 /* Returns true if the typeinfo for type should be placed in
972 the runtime library. */
975 typeinfo_in_lib_p (tree type)
977 /* The typeinfo objects for `T*' and `const T*' are in the runtime
978 library for simple types T. */
979 if (TREE_CODE (type) == POINTER_TYPE
980 && (cp_type_quals (TREE_TYPE (type)) == TYPE_QUAL_CONST
981 || cp_type_quals (TREE_TYPE (type)) == TYPE_UNQUALIFIED))
982 type = TREE_TYPE (type);
984 switch (TREE_CODE (type))
997 /* Generate the initializer for the type info describing TYPE. TK_INDEX is
998 the index of the descriptor in the tinfo_desc vector. */
1001 get_pseudo_ti_init (tree type, unsigned tk_index)
1003 tinfo_s *ti = VEC_index (tinfo_s, tinfo_descs, tk_index);
1005 gcc_assert (at_eof);
1008 case TK_POINTER_MEMBER_TYPE:
1009 return ptm_initializer (ti, type);
1011 case TK_POINTER_TYPE:
1012 return ptr_initializer (ti, type);
1014 case TK_BUILTIN_TYPE:
1015 case TK_ENUMERAL_TYPE:
1016 case TK_FUNCTION_TYPE:
1018 return generic_initializer (ti, type);
1021 return class_initializer (ti, type, NULL_TREE);
1023 case TK_SI_CLASS_TYPE:
1025 tree base_binfo = BINFO_BASE_BINFO (TYPE_BINFO (type), 0);
1026 tree tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1027 tree base_inits = tree_cons (NULL_TREE, tinfo, NULL_TREE);
1029 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1030 ti = VEC_index (tinfo_s, tinfo_descs, tk_index);
1031 return class_initializer (ti, type, base_inits);
1036 int hint = ((CLASSTYPE_REPEATED_BASE_P (type) << 0)
1037 | (CLASSTYPE_DIAMOND_SHAPED_P (type) << 1));
1038 tree binfo = TYPE_BINFO (type);
1039 int nbases = BINFO_N_BASE_BINFOS (binfo);
1040 VEC(tree,gc) *base_accesses = BINFO_BASE_ACCESSES (binfo);
1041 tree base_inits = NULL_TREE;
1044 gcc_assert (tk_index >= TK_FIXED);
1046 /* Generate the base information initializer. */
1047 for (ix = nbases; ix--;)
1049 tree base_binfo = BINFO_BASE_BINFO (binfo, ix);
1050 tree base_init = NULL_TREE;
1055 if (VEC_index (tree, base_accesses, ix) == access_public_node)
1057 tinfo = get_tinfo_ptr (BINFO_TYPE (base_binfo));
1058 if (BINFO_VIRTUAL_P (base_binfo))
1060 /* We store the vtable offset at which the virtual
1061 base offset can be found. */
1062 offset = BINFO_VPTR_FIELD (base_binfo);
1063 offset = convert (sizetype, offset);
1067 offset = BINFO_OFFSET (base_binfo);
1069 /* Combine offset and flags into one field. */
1070 offset = cp_build_binary_op (LSHIFT_EXPR, offset,
1071 build_int_cst (NULL_TREE, 8));
1072 offset = cp_build_binary_op (BIT_IOR_EXPR, offset,
1073 build_int_cst (NULL_TREE, flags));
1074 base_init = tree_cons (NULL_TREE, offset, base_init);
1075 base_init = tree_cons (NULL_TREE, tinfo, base_init);
1076 base_init = build_constructor_from_list (NULL_TREE, base_init);
1077 base_inits = tree_cons (NULL_TREE, base_init, base_inits);
1079 base_inits = build_constructor_from_list (NULL_TREE, base_inits);
1080 base_inits = tree_cons (NULL_TREE, base_inits, NULL_TREE);
1081 /* Prepend the number of bases. */
1082 base_inits = tree_cons (NULL_TREE,
1083 build_int_cst (NULL_TREE, nbases),
1085 /* Prepend the hint flags. */
1086 base_inits = tree_cons (NULL_TREE,
1087 build_int_cst (NULL_TREE, hint),
1090 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1091 ti = VEC_index (tinfo_s, tinfo_descs, tk_index);
1092 return class_initializer (ti, type, base_inits);
1097 /* Generate the RECORD_TYPE containing the data layout of a type_info
1098 derivative as used by the runtime. This layout must be consistent with
1099 that defined in the runtime support. Also generate the VAR_DECL for the
1100 type's vtable. We explicitly manage the vtable member, and name it for
1101 real type as used in the runtime. The RECORD type has a different name,
1102 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1103 is the generated type and TINFO_VTABLE_NAME is the name of the
1104 vtable. We have to delay generating the VAR_DECL of the vtable
1105 until the end of the translation, when we'll have seen the library
1106 definition, if there was one.
1108 REAL_NAME is the runtime's name of the type. Trailing arguments are
1109 additional FIELD_DECL's for the structure. The final argument must be
1113 create_pseudo_type_info (int tk, const char *real_name, ...)
1122 va_start (ap, real_name);
1124 /* Generate the pseudo type name. */
1125 pseudo_name = (char *) alloca (strlen (real_name) + 30);
1126 strcpy (pseudo_name, real_name);
1127 strcat (pseudo_name, "_pseudo");
1129 sprintf (pseudo_name + strlen (pseudo_name), "%d", tk - TK_FIXED);
1131 /* First field is the pseudo type_info base class. */
1132 fields = build_decl (FIELD_DECL, NULL_TREE,
1133 VEC_index (tinfo_s, tinfo_descs,
1134 TK_TYPE_INFO_TYPE)->type);
1136 /* Now add the derived fields. */
1137 while ((field_decl = va_arg (ap, tree)))
1139 TREE_CHAIN (field_decl) = fields;
1140 fields = field_decl;
1143 /* Create the pseudo type. */
1144 pseudo_type = make_aggr_type (RECORD_TYPE);
1145 finish_builtin_struct (pseudo_type, pseudo_name, fields, NULL_TREE);
1146 CLASSTYPE_AS_BASE (pseudo_type) = pseudo_type;
1148 ti = VEC_index (tinfo_s, tinfo_descs, tk);
1149 ti->type = cp_build_qualified_type (pseudo_type, TYPE_QUAL_CONST);
1150 ti->name = get_identifier (real_name);
1151 ti->vtable = NULL_TREE;
1153 /* Pretend this is public so determine_visibility doesn't give vtables
1154 internal linkage. */
1155 TREE_PUBLIC (TYPE_MAIN_DECL (ti->type)) = 1;
1160 /* Return the index of a pseudo type info type node used to describe
1161 TYPE. TYPE must be a complete type (or cv void), except at the end
1162 of the translation unit. */
1165 get_pseudo_ti_index (tree type)
1169 switch (TREE_CODE (type))
1172 ix = TK_POINTER_MEMBER_TYPE;
1176 ix = TK_POINTER_TYPE;
1180 ix = TK_ENUMERAL_TYPE;
1184 ix = TK_FUNCTION_TYPE;
1193 if (TYPE_PTRMEMFUNC_P (type))
1195 ix = TK_POINTER_MEMBER_TYPE;
1198 else if (!COMPLETE_TYPE_P (type))
1201 cxx_incomplete_type_error (NULL_TREE, type);
1205 else if (!BINFO_N_BASE_BINFOS (TYPE_BINFO (type)))
1212 tree binfo = TYPE_BINFO (type);
1213 VEC(tree,gc) *base_accesses = BINFO_BASE_ACCESSES (binfo);
1214 tree base_binfo = BINFO_BASE_BINFO (binfo, 0);
1215 int num_bases = BINFO_N_BASE_BINFOS (binfo);
1218 && VEC_index (tree, base_accesses, 0) == access_public_node
1219 && !BINFO_VIRTUAL_P (base_binfo)
1220 && integer_zerop (BINFO_OFFSET (base_binfo)))
1222 /* single non-virtual public. */
1223 ix = TK_SI_CLASS_TYPE;
1229 tree array_domain, base_array;
1231 ix = TK_FIXED + num_bases;
1232 if (VEC_length (tinfo_s, tinfo_descs) <= ix)
1234 /* too short, extend. */
1235 unsigned len = VEC_length (tinfo_s, tinfo_descs);
1237 VEC_safe_grow (tinfo_s, gc, tinfo_descs, ix + 1);
1238 while (VEC_iterate (tinfo_s, tinfo_descs, len++, ti))
1239 ti->type = ti->vtable = ti->name = NULL_TREE;
1241 else if (VEC_index (tinfo_s, tinfo_descs, ix)->type)
1242 /* already created. */
1245 /* Create the array of __base_class_type_info entries.
1246 G++ 3.2 allocated an array that had one too many
1247 entries, and then filled that extra entries with
1249 if (abi_version_at_least (2))
1250 array_domain = build_index_type (size_int (num_bases - 1));
1252 array_domain = build_index_type (size_int (num_bases));
1254 build_array_type (VEC_index (tinfo_s, tinfo_descs,
1255 TK_BASE_TYPE)->type,
1258 push_nested_namespace (abi_node);
1259 create_pseudo_type_info
1260 (ix, "__vmi_class_type_info",
1261 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1262 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1263 build_decl (FIELD_DECL, NULL_TREE, base_array),
1265 pop_nested_namespace (abi_node);
1270 ix = TK_BUILTIN_TYPE;
1276 /* Make sure the required builtin types exist for generating the type_info
1277 variable definitions. */
1280 create_tinfo_types (void)
1284 gcc_assert (!tinfo_descs);
1286 VEC_safe_grow (tinfo_s, gc, tinfo_descs, TK_FIXED);
1288 push_nested_namespace (abi_node);
1290 /* Create the internal type_info structure. This is used as a base for
1291 the other structures. */
1295 field = build_decl (FIELD_DECL, NULL_TREE, const_ptr_type_node);
1298 field = build_decl (FIELD_DECL, NULL_TREE, const_string_type_node);
1299 TREE_CHAIN (field) = fields;
1302 ti = VEC_index (tinfo_s, tinfo_descs, TK_TYPE_INFO_TYPE);
1303 ti->type = make_aggr_type (RECORD_TYPE);
1304 ti->vtable = NULL_TREE;
1305 ti->name = NULL_TREE;
1306 finish_builtin_struct (ti->type, "__type_info_pseudo",
1308 TYPE_HAS_CONSTRUCTOR (ti->type) = 1;
1311 /* Fundamental type_info */
1312 create_pseudo_type_info (TK_BUILTIN_TYPE, "__fundamental_type_info", NULL);
1314 /* Array, function and enum type_info. No additional fields. */
1315 create_pseudo_type_info (TK_ARRAY_TYPE, "__array_type_info", NULL);
1316 create_pseudo_type_info (TK_FUNCTION_TYPE, "__function_type_info", NULL);
1317 create_pseudo_type_info (TK_ENUMERAL_TYPE, "__enum_type_info", NULL);
1319 /* Class type_info. No additional fields. */
1320 create_pseudo_type_info (TK_CLASS_TYPE, "__class_type_info", NULL);
1322 /* Single public non-virtual base class. Add pointer to base class.
1323 This is really a descendant of __class_type_info. */
1324 create_pseudo_type_info (TK_SI_CLASS_TYPE, "__si_class_type_info",
1325 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1328 /* Base class internal helper. Pointer to base type, offset to base,
1333 field = build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type);
1336 field = build_decl (FIELD_DECL, NULL_TREE, integer_types[itk_long]);
1337 TREE_CHAIN (field) = fields;
1340 ti = VEC_index (tinfo_s, tinfo_descs, TK_BASE_TYPE);
1342 ti->type = make_aggr_type (RECORD_TYPE);
1343 ti->vtable = NULL_TREE;
1344 ti->name = NULL_TREE;
1345 finish_builtin_struct (ti->type, "__base_class_type_info_pseudo",
1347 TYPE_HAS_CONSTRUCTOR (ti->type) = 1;
1350 /* Pointer type_info. Adds two fields, qualification mask
1351 and pointer to the pointed to type. This is really a descendant of
1352 __pbase_type_info. */
1353 create_pseudo_type_info (TK_POINTER_TYPE, "__pointer_type_info",
1354 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1355 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1358 /* Pointer to member data type_info. Add qualifications flags,
1359 pointer to the member's type info and pointer to the class.
1360 This is really a descendant of __pbase_type_info. */
1361 create_pseudo_type_info (TK_POINTER_MEMBER_TYPE,
1362 "__pointer_to_member_type_info",
1363 build_decl (FIELD_DECL, NULL_TREE, integer_type_node),
1364 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1365 build_decl (FIELD_DECL, NULL_TREE, type_info_ptr_type),
1368 pop_nested_namespace (abi_node);
1371 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1372 support. Generating them here guarantees consistency with the other
1373 structures. We use the following heuristic to determine when the runtime
1374 is being generated. If std::__fundamental_type_info is defined, and its
1375 destructor is defined, then the runtime is being built. */
1378 emit_support_tinfos (void)
1380 static tree *const fundamentals[] =
1385 &char_type_node, &signed_char_type_node, &unsigned_char_type_node,
1386 &short_integer_type_node, &short_unsigned_type_node,
1387 &integer_type_node, &unsigned_type_node,
1388 &long_integer_type_node, &long_unsigned_type_node,
1389 &long_long_integer_type_node, &long_long_unsigned_type_node,
1390 &float_type_node, &double_type_node, &long_double_type_node,
1394 tree bltn_type, dtor;
1396 push_nested_namespace (abi_node);
1397 bltn_type = xref_tag (class_type,
1398 get_identifier ("__fundamental_type_info"),
1399 /*tag_scope=*/ts_current, false);
1400 pop_nested_namespace (abi_node);
1401 if (!COMPLETE_TYPE_P (bltn_type))
1403 dtor = CLASSTYPE_DESTRUCTORS (bltn_type);
1404 if (!dtor || DECL_EXTERNAL (dtor))
1407 for (ix = 0; fundamentals[ix]; ix++)
1409 tree bltn = *fundamentals[ix];
1414 types[1] = build_pointer_type (bltn);
1415 types[2] = build_pointer_type (build_qualified_type (bltn,
1418 for (i = 0; i < 3; ++i)
1422 tinfo = get_tinfo_decl (types[i]);
1423 TREE_USED (tinfo) = 1;
1424 mark_needed (tinfo);
1425 /* The C++ ABI requires that these objects be COMDAT. But,
1426 On systems without weak symbols, initialized COMDAT
1427 objects are emitted with internal linkage. (See
1428 comdat_linkage for details.) Since we want these objects
1429 to have external linkage so that copies do not have to be
1430 emitted in code outside the runtime library, we make them
1433 It might also not be necessary to follow this detail of the
1435 if (!flag_weak || ! targetm.cxx.library_rtti_comdat ())
1437 gcc_assert (TREE_PUBLIC (tinfo) && !DECL_COMDAT (tinfo));
1438 DECL_INTERFACE_KNOWN (tinfo) = 1;
1444 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1445 tinfo decl. Determine whether it needs emitting, and if so
1446 generate the initializer. */
1449 emit_tinfo_decl (tree decl)
1451 tree type = TREE_TYPE (DECL_NAME (decl));
1452 int in_library = typeinfo_in_lib_p (type);
1454 gcc_assert (DECL_TINFO_P (decl));
1459 DECL_EXTERNAL (decl) = 0;
1462 /* If we're not in the runtime, then DECL (which is already
1463 DECL_EXTERNAL) will not be defined here. */
1464 DECL_INTERFACE_KNOWN (decl) = 1;
1468 else if (involves_incomplete_p (type))
1470 if (!decl_needed_p (decl))
1472 /* If TYPE involves an incomplete class type, then the typeinfo
1473 object will be emitted with internal linkage. There is no
1474 way to know whether or not types are incomplete until the end
1475 of the compilation, so this determination must be deferred
1476 until this point. */
1477 TREE_PUBLIC (decl) = 0;
1478 DECL_EXTERNAL (decl) = 0;
1479 DECL_INTERFACE_KNOWN (decl) = 1;
1482 import_export_decl (decl);
1483 if (DECL_NOT_REALLY_EXTERN (decl) && decl_needed_p (decl))
1487 DECL_EXTERNAL (decl) = 0;
1488 init = get_pseudo_ti_init (type, get_pseudo_ti_index (type));
1489 DECL_INITIAL (decl) = init;
1491 finish_decl (decl, init, NULL_TREE);
1498 #include "gt-cp-rtti.h"