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 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
25 #include "coretypes.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 /* Auxiliary data we hold for each type_info derived object we need. */
66 typedef struct tinfo_s
GTY (())
68 tree type
; /* The RECORD_TYPE for this type_info object */
70 tree vtable
; /* The VAR_DECL of the vtable. Only filled at end of
73 tree name
; /* IDENTIFIER_NODE for the ABI specified name of
74 the type_info derived type. */
78 DEF_VEC_ALLOC_O(tinfo_s
,gc
);
80 typedef enum tinfo_kind
82 TK_TYPE_INFO_TYPE
, /* std::type_info */
83 TK_BASE_TYPE
, /* abi::__base_class_type_info */
84 TK_BUILTIN_TYPE
, /* abi::__fundamental_type_info */
85 TK_ARRAY_TYPE
, /* abi::__array_type_info */
86 TK_FUNCTION_TYPE
, /* abi::__function_type_info */
87 TK_ENUMERAL_TYPE
, /* abi::__enum_type_info */
88 TK_POINTER_TYPE
, /* abi::__pointer_type_info */
89 TK_POINTER_MEMBER_TYPE
, /* abi::__pointer_to_member_type_info */
90 TK_CLASS_TYPE
, /* abi::__class_type_info */
91 TK_SI_CLASS_TYPE
, /* abi::__si_class_type_info */
92 TK_FIXED
/* end of fixed descriptors. */
93 /* ... abi::__vmi_type_info<I> */
96 /* A vector of all tinfo decls that haven't yet been emitted. */
97 VEC(tree
,gc
) *unemitted_tinfo_decls
;
99 /* A vector of all type_info derived types we need. The first few are
100 fixed and created early. The remainder are for multiple inheritance
101 and are generated as needed. */
102 static GTY (()) VEC(tinfo_s
,gc
) *tinfo_descs
;
104 static tree
ifnonnull (tree
, tree
);
105 static tree
tinfo_name (tree
);
106 static tree
build_dynamic_cast_1 (tree
, tree
);
107 static tree
throw_bad_cast (void);
108 static tree
throw_bad_typeid (void);
109 static tree
get_tinfo_decl_dynamic (tree
);
110 static tree
get_tinfo_ptr (tree
);
111 static bool typeid_ok_p (void);
112 static int qualifier_flags (tree
);
113 static bool target_incomplete_p (tree
);
114 static tree
tinfo_base_init (tinfo_s
*, tree
);
115 static tree
generic_initializer (tinfo_s
*, tree
);
116 static tree
ptr_initializer (tinfo_s
*, tree
);
117 static tree
ptm_initializer (tinfo_s
*, tree
);
118 static tree
class_initializer (tinfo_s
*, tree
, tree
);
119 static void create_pseudo_type_info (int, const char *, ...);
120 static tree
get_pseudo_ti_init (tree
, unsigned);
121 static unsigned get_pseudo_ti_index (tree
);
122 static void create_tinfo_types (void);
123 static bool typeinfo_in_lib_p (tree
);
125 static int doing_runtime
= 0;
128 /* Declare language defined type_info type and a pointer to const
129 type_info. This is incomplete here, and will be completed when
130 the user #includes <typeinfo>. There are language defined
131 restrictions on what can be done until that is included. Create
132 the internal versions of the ABI types. */
135 init_rtti_processing (void)
139 push_namespace (std_identifier
);
140 type_info_type
= xref_tag (class_type
, get_identifier ("type_info"),
141 /*tag_scope=*/ts_current
, false);
143 const_type_info_type_node
144 = build_qualified_type (type_info_type
, TYPE_QUAL_CONST
);
145 type_info_ptr_type
= build_pointer_type (const_type_info_type_node
);
147 unemitted_tinfo_decls
= VEC_alloc (tree
, gc
, 124);
149 create_tinfo_types ();
152 /* Given the expression EXP of type `class *', return the head of the
153 object pointed to by EXP with type cv void*, if the class has any
154 virtual functions (TYPE_POLYMORPHIC_P), else just return the
158 build_headof (tree exp
)
160 tree type
= TREE_TYPE (exp
);
164 gcc_assert (TREE_CODE (type
) == POINTER_TYPE
);
165 type
= TREE_TYPE (type
);
167 if (!TYPE_POLYMORPHIC_P (type
))
170 /* We use this a couple of times below, protect it. */
171 exp
= save_expr (exp
);
173 /* The offset-to-top field is at index -2 from the vptr. */
174 index
= build_int_cst (NULL_TREE
,
175 -2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
);
177 offset
= build_vtbl_ref (build_indirect_ref (exp
, NULL
), index
);
179 type
= build_qualified_type (ptr_type_node
,
180 cp_type_quals (TREE_TYPE (exp
)));
181 return build2 (POINTER_PLUS_EXPR
, type
, exp
,
182 convert_to_integer (sizetype
, offset
));
185 /* Get a bad_cast node for the program to throw...
187 See libstdc++/exception.cc for __throw_bad_cast */
190 throw_bad_cast (void)
192 tree fn
= get_identifier ("__cxa_bad_cast");
193 if (!get_global_value_if_present (fn
, &fn
))
194 fn
= push_throw_library_fn (fn
, build_function_type (ptr_type_node
,
197 return build_cxx_call (fn
, 0, NULL
);
200 /* Return an expression for "__cxa_bad_typeid()". The expression
201 returned is an lvalue of type "const std::type_info". */
204 throw_bad_typeid (void)
206 tree fn
= get_identifier ("__cxa_bad_typeid");
207 if (!get_global_value_if_present (fn
, &fn
))
211 t
= build_reference_type (const_type_info_type_node
);
212 t
= build_function_type (t
, void_list_node
);
213 fn
= push_throw_library_fn (fn
, t
);
216 return build_cxx_call (fn
, 0, NULL
);
219 /* Return an lvalue expression whose type is "const std::type_info"
220 and whose value indicates the type of the expression EXP. If EXP
221 is a reference to a polymorphic class, return the dynamic type;
222 otherwise return the static type of the expression. */
225 get_tinfo_decl_dynamic (tree exp
)
230 if (error_operand_p (exp
))
231 return error_mark_node
;
233 /* peel back references, so they match. */
234 type
= non_reference (TREE_TYPE (exp
));
236 /* Peel off cv qualifiers. */
237 type
= TYPE_MAIN_VARIANT (type
);
239 if (CLASS_TYPE_P (type
))
240 type
= complete_type_or_else (type
, exp
);
243 return error_mark_node
;
245 /* If exp is a reference to polymorphic type, get the real type_info. */
246 if (TYPE_POLYMORPHIC_P (type
) && ! resolves_to_fixed_type_p (exp
, 0))
248 /* build reference to type_info from vtable. */
251 /* The RTTI information is at index -1. */
252 index
= build_int_cst (NULL_TREE
,
253 -1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
);
254 t
= build_vtbl_ref (exp
, index
);
255 t
= convert (type_info_ptr_type
, t
);
258 /* Otherwise return the type_info for the static type of the expr. */
259 t
= get_tinfo_ptr (TYPE_MAIN_VARIANT (type
));
261 return build_indirect_ref (t
, NULL
);
269 error ("cannot use typeid with -fno-rtti");
273 if (!COMPLETE_TYPE_P (const_type_info_type_node
))
275 error ("must #include <typeinfo> before using typeid");
282 /* Return an expression for "typeid(EXP)". The expression returned is
283 an lvalue of type "const std::type_info". */
286 build_typeid (tree exp
)
288 tree cond
= NULL_TREE
;
291 if (exp
== error_mark_node
|| !typeid_ok_p ())
292 return error_mark_node
;
294 if (processing_template_decl
)
295 return build_min (TYPEID_EXPR
, const_type_info_type_node
, exp
);
297 if (TREE_CODE (exp
) == INDIRECT_REF
298 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == POINTER_TYPE
299 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp
))
300 && ! resolves_to_fixed_type_p (exp
, &nonnull
)
303 exp
= stabilize_reference (exp
);
304 cond
= cp_convert (boolean_type_node
, TREE_OPERAND (exp
, 0));
307 exp
= get_tinfo_decl_dynamic (exp
);
309 if (exp
== error_mark_node
)
310 return error_mark_node
;
314 tree bad
= throw_bad_typeid ();
316 exp
= build3 (COND_EXPR
, TREE_TYPE (exp
), cond
, exp
, bad
);
322 /* Generate the NTBS name of a type. */
324 tinfo_name (tree type
)
329 name
= mangle_type_string (type
);
330 name_string
= fix_string_type (build_string (strlen (name
) + 1, name
));
334 /* Return a VAR_DECL for the internal ABI defined type_info object for
335 TYPE. You must arrange that the decl is mark_used, if actually use
336 it --- decls in vtables are only used if the vtable is output. */
339 get_tinfo_decl (tree type
)
344 if (variably_modified_type_p (type
, /*fn=*/NULL_TREE
))
346 error ("cannot create type information for type %qT because "
347 "it involves types of variable size",
349 return error_mark_node
;
352 if (TREE_CODE (type
) == METHOD_TYPE
)
353 type
= build_function_type (TREE_TYPE (type
),
354 TREE_CHAIN (TYPE_ARG_TYPES (type
)));
356 /* For a class type, the variable is cached in the type node
358 if (CLASS_TYPE_P (type
))
360 d
= CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
));
365 name
= mangle_typeinfo_for_type (type
);
367 d
= IDENTIFIER_GLOBAL_VALUE (name
);
370 int ix
= get_pseudo_ti_index (type
);
371 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, ix
);
373 d
= build_lang_decl (VAR_DECL
, name
, ti
->type
);
374 SET_DECL_ASSEMBLER_NAME (d
, name
);
375 /* Remember the type it is for. */
376 TREE_TYPE (name
) = type
;
377 DECL_TINFO_P (d
) = 1;
378 DECL_ARTIFICIAL (d
) = 1;
379 DECL_IGNORED_P (d
) = 1;
380 TREE_READONLY (d
) = 1;
382 /* Mark the variable as undefined -- but remember that we can
383 define it later if we need to do so. */
384 DECL_EXTERNAL (d
) = 1;
385 DECL_NOT_REALLY_EXTERN (d
) = 1;
386 set_linkage_according_to_type (type
, d
);
388 d
= pushdecl_top_level_and_finish (d
, NULL_TREE
);
389 if (CLASS_TYPE_P (type
))
390 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
)) = d
;
392 /* Add decl to the global array of tinfo decls. */
393 VEC_safe_push (tree
, gc
, unemitted_tinfo_decls
, d
);
399 /* Return a pointer to a type_info object describing TYPE, suitably
400 cast to the language defined type. */
403 get_tinfo_ptr (tree type
)
405 tree decl
= get_tinfo_decl (type
);
408 return build_nop (type_info_ptr_type
,
409 build_address (decl
));
412 /* Return the type_info object for TYPE. */
415 get_typeid (tree type
)
417 if (type
== error_mark_node
|| !typeid_ok_p ())
418 return error_mark_node
;
420 if (processing_template_decl
)
421 return build_min (TYPEID_EXPR
, const_type_info_type_node
, type
);
423 /* If the type of the type-id is a reference type, the result of the
424 typeid expression refers to a type_info object representing the
426 type
= non_reference (type
);
428 /* The top-level cv-qualifiers of the lvalue expression or the type-id
429 that is the operand of typeid are always ignored. */
430 type
= TYPE_MAIN_VARIANT (type
);
432 if (CLASS_TYPE_P (type
))
433 type
= complete_type_or_else (type
, NULL_TREE
);
436 return error_mark_node
;
438 return build_indirect_ref (get_tinfo_ptr (type
), NULL
);
441 /* Check whether TEST is null before returning RESULT. If TEST is used in
442 RESULT, it must have previously had a save_expr applied to it. */
445 ifnonnull (tree test
, tree result
)
447 return build3 (COND_EXPR
, TREE_TYPE (result
),
448 build2 (EQ_EXPR
, boolean_type_node
, test
,
449 cp_convert (TREE_TYPE (test
), integer_zero_node
)),
450 cp_convert (TREE_TYPE (result
), integer_zero_node
),
454 /* Execute a dynamic cast, as described in section 5.2.6 of the 9/93 working
458 build_dynamic_cast_1 (tree type
, tree expr
)
460 enum tree_code tc
= TREE_CODE (type
);
461 tree exprtype
= TREE_TYPE (expr
);
463 tree old_expr
= expr
;
464 const char *errstr
= NULL
;
466 /* Save casted types in the function's used types hash table. */
467 used_types_insert (type
);
469 /* T shall be a pointer or reference to a complete class type, or
470 `pointer to cv void''. */
474 if (TREE_CODE (TREE_TYPE (type
)) == VOID_TYPE
)
478 if (! IS_AGGR_TYPE (TREE_TYPE (type
)))
480 errstr
= "target is not pointer or reference to class";
483 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type
))))
485 errstr
= "target is not pointer or reference to complete type";
491 errstr
= "target is not pointer or reference";
495 if (tc
== POINTER_TYPE
)
497 /* If T is a pointer type, v shall be an rvalue of a pointer to
498 complete class type, and the result is an rvalue of type T. */
500 if (TREE_CODE (exprtype
) != POINTER_TYPE
)
502 errstr
= "source is not a pointer";
505 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
507 errstr
= "source is not a pointer to class";
510 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
512 errstr
= "source is a pointer to incomplete type";
518 exprtype
= build_reference_type (exprtype
);
520 /* T is a reference type, v shall be an lvalue of a complete class
521 type, and the result is an lvalue of the type referred to by T. */
523 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
525 errstr
= "source is not of class type";
528 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
530 errstr
= "source is of incomplete class type";
534 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
535 expr
= convert_to_reference (exprtype
, expr
, CONV_IMPLICIT
,
536 LOOKUP_NORMAL
, NULL_TREE
);
539 /* The dynamic_cast operator shall not cast away constness. */
540 if (!at_least_as_qualified_p (TREE_TYPE (type
),
541 TREE_TYPE (exprtype
)))
543 errstr
= "conversion casts away constness";
547 /* If *type is an unambiguous accessible base class of *exprtype,
548 convert statically. */
552 binfo
= lookup_base (TREE_TYPE (exprtype
), TREE_TYPE (type
),
557 expr
= build_base_path (PLUS_EXPR
, convert_from_reference (expr
),
559 if (TREE_CODE (exprtype
) == POINTER_TYPE
)
560 expr
= rvalue (expr
);
565 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
566 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype
)))
569 /* if TYPE is `void *', return pointer to complete object. */
570 if (tc
== POINTER_TYPE
&& VOID_TYPE_P (TREE_TYPE (type
)))
572 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
573 if (TREE_CODE (expr
) == ADDR_EXPR
574 && TREE_CODE (TREE_OPERAND (expr
, 0)) == VAR_DECL
575 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == RECORD_TYPE
)
576 return build1 (NOP_EXPR
, type
, expr
);
578 /* Since expr is used twice below, save it. */
579 expr
= save_expr (expr
);
581 expr1
= build_headof (expr
);
582 if (TREE_TYPE (expr1
) != type
)
583 expr1
= build1 (NOP_EXPR
, type
, expr1
);
584 return ifnonnull (expr
, expr1
);
589 tree result
, td2
, td3
;
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);
653 dcast_fn
= dynamic_cast_node
;
661 push_nested_namespace (ns
);
662 tinfo_ptr
= xref_tag (class_type
,
663 get_identifier ("__class_type_info"),
664 /*tag_scope=*/ts_current
, false);
666 tinfo_ptr
= build_pointer_type
667 (build_qualified_type
668 (tinfo_ptr
, TYPE_QUAL_CONST
));
669 name
= "__dynamic_cast";
671 (NULL_TREE
, const_ptr_type_node
, tree_cons
672 (NULL_TREE
, tinfo_ptr
, tree_cons
673 (NULL_TREE
, tinfo_ptr
, tree_cons
674 (NULL_TREE
, ptrdiff_type_node
, void_list_node
))));
675 tmp
= build_function_type (ptr_type_node
, tmp
);
676 dcast_fn
= build_library_fn_ptr (name
, tmp
);
677 DECL_IS_PURE (dcast_fn
) = 1;
678 pop_nested_namespace (ns
);
679 dynamic_cast_node
= dcast_fn
;
681 result
= build_cxx_call (dcast_fn
, 4, elems
);
683 if (tc
== REFERENCE_TYPE
)
685 tree bad
= throw_bad_cast ();
688 result
= save_expr (result
);
689 neq
= c_common_truthvalue_conversion (result
);
690 return build3 (COND_EXPR
, type
, neq
, result
, bad
);
693 /* Now back to the type we want from a void*. */
694 result
= cp_convert (type
, result
);
695 return ifnonnull (expr
, result
);
699 errstr
= "source type is not polymorphic";
702 error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
703 expr
, exprtype
, type
, errstr
);
704 return error_mark_node
;
708 build_dynamic_cast (tree type
, tree expr
)
710 if (type
== error_mark_node
|| expr
== error_mark_node
)
711 return error_mark_node
;
713 if (processing_template_decl
)
715 expr
= build_min (DYNAMIC_CAST_EXPR
, type
, expr
);
716 TREE_SIDE_EFFECTS (expr
) = 1;
721 return convert_from_reference (build_dynamic_cast_1 (type
, expr
));
724 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
727 qualifier_flags (tree type
)
730 int quals
= cp_type_quals (type
);
732 if (quals
& TYPE_QUAL_CONST
)
734 if (quals
& TYPE_QUAL_VOLATILE
)
736 if (quals
& TYPE_QUAL_RESTRICT
)
741 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
742 contains a pointer to member of an incomplete class. */
745 target_incomplete_p (tree type
)
748 if (TYPE_PTRMEM_P (type
))
750 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)))
752 type
= TYPE_PTRMEM_POINTED_TO_TYPE (type
);
754 else if (TREE_CODE (type
) == POINTER_TYPE
)
755 type
= TREE_TYPE (type
);
757 return !COMPLETE_OR_VOID_TYPE_P (type
);
760 /* Returns true if TYPE involves an incomplete class type; in that
761 case, typeinfo variables for TYPE should be emitted with internal
765 involves_incomplete_p (tree type
)
767 switch (TREE_CODE (type
))
770 return target_incomplete_p (TREE_TYPE (type
));
775 (target_incomplete_p (TYPE_PTRMEM_POINTED_TO_TYPE (type
))
776 || !COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)));
779 if (TYPE_PTRMEMFUNC_P (type
))
783 if (!COMPLETE_TYPE_P (type
))
787 /* All other types do not involve incomplete class types. */
792 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
793 is the vtable pointer and NTBS name. The NTBS name is emitted as a
794 comdat const char array, so it becomes a unique key for the type. Generate
795 and emit that VAR_DECL here. (We can't always emit the type_info itself
796 as comdat, because of pointers to incomplete.) */
799 tinfo_base_init (tinfo_s
*ti
, tree target
)
801 tree init
= NULL_TREE
;
808 /* Generate the NTBS array variable. */
809 tree name_type
= build_cplus_array_type
810 (build_qualified_type (char_type_node
, TYPE_QUAL_CONST
),
812 tree name_string
= tinfo_name (target
);
814 /* Determine the name of the variable -- and remember with which
815 type it is associated. */
816 name_name
= mangle_typeinfo_string_for_type (target
);
817 TREE_TYPE (name_name
) = target
;
819 name_decl
= build_lang_decl (VAR_DECL
, name_name
, name_type
);
820 SET_DECL_ASSEMBLER_NAME (name_decl
, name_name
);
821 DECL_ARTIFICIAL (name_decl
) = 1;
822 DECL_IGNORED_P (name_decl
) = 1;
823 TREE_READONLY (name_decl
) = 1;
824 TREE_STATIC (name_decl
) = 1;
825 DECL_EXTERNAL (name_decl
) = 0;
826 DECL_TINFO_P (name_decl
) = 1;
827 set_linkage_according_to_type (target
, name_decl
);
828 import_export_decl (name_decl
);
829 DECL_INITIAL (name_decl
) = name_string
;
830 mark_used (name_decl
);
831 pushdecl_top_level_and_finish (name_decl
, name_string
);
834 vtable_ptr
= ti
->vtable
;
838 push_nested_namespace (abi_node
);
839 real_type
= xref_tag (class_type
, ti
->name
,
840 /*tag_scope=*/ts_current
, false);
841 pop_nested_namespace (abi_node
);
843 if (!COMPLETE_TYPE_P (real_type
))
845 /* We never saw a definition of this type, so we need to
846 tell the compiler that this is an exported class, as
847 indeed all of the __*_type_info classes are. */
848 SET_CLASSTYPE_INTERFACE_KNOWN (real_type
);
849 CLASSTYPE_INTERFACE_ONLY (real_type
) = 1;
852 vtable_ptr
= get_vtable_decl (real_type
, /*complete=*/1);
853 vtable_ptr
= build_unary_op (ADDR_EXPR
, vtable_ptr
, 0);
855 /* We need to point into the middle of the vtable. */
857 (POINTER_PLUS_EXPR
, TREE_TYPE (vtable_ptr
), vtable_ptr
,
858 size_binop (MULT_EXPR
,
859 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
),
860 TYPE_SIZE_UNIT (vtable_entry_type
)));
862 ti
->vtable
= vtable_ptr
;
865 init
= tree_cons (NULL_TREE
, vtable_ptr
, init
);
867 init
= tree_cons (NULL_TREE
, decay_conversion (name_decl
), init
);
869 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
870 TREE_CONSTANT (init
) = 1;
871 TREE_INVARIANT (init
) = 1;
872 TREE_STATIC (init
) = 1;
873 init
= tree_cons (NULL_TREE
, init
, NULL_TREE
);
878 /* Return the CONSTRUCTOR expr for a type_info of TYPE. TI provides the
879 information about the particular type_info derivation, which adds no
880 additional fields to the type_info base. */
883 generic_initializer (tinfo_s
*ti
, tree target
)
885 tree init
= tinfo_base_init (ti
, target
);
887 init
= build_constructor_from_list (NULL_TREE
, init
);
888 TREE_CONSTANT (init
) = 1;
889 TREE_INVARIANT (init
) = 1;
890 TREE_STATIC (init
) = 1;
894 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
895 TI provides information about the particular type_info derivation,
896 which adds target type and qualifier flags members to the type_info base. */
899 ptr_initializer (tinfo_s
*ti
, tree target
)
901 tree init
= tinfo_base_init (ti
, target
);
902 tree to
= TREE_TYPE (target
);
903 int flags
= qualifier_flags (to
);
904 bool incomplete
= target_incomplete_p (to
);
908 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
909 init
= tree_cons (NULL_TREE
,
910 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
913 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
914 TREE_CONSTANT (init
) = 1;
915 TREE_INVARIANT (init
) = 1;
916 TREE_STATIC (init
) = 1;
920 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
921 TI provides information about the particular type_info derivation,
922 which adds class, target type and qualifier flags members to the type_info
926 ptm_initializer (tinfo_s
*ti
, tree target
)
928 tree init
= tinfo_base_init (ti
, target
);
929 tree to
= TYPE_PTRMEM_POINTED_TO_TYPE (target
);
930 tree klass
= TYPE_PTRMEM_CLASS_TYPE (target
);
931 int flags
= qualifier_flags (to
);
932 bool incomplete
= target_incomplete_p (to
);
936 if (!COMPLETE_TYPE_P (klass
))
938 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
939 init
= tree_cons (NULL_TREE
,
940 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
942 init
= tree_cons (NULL_TREE
,
943 get_tinfo_ptr (klass
),
946 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
947 TREE_CONSTANT (init
) = 1;
948 TREE_INVARIANT (init
) = 1;
949 TREE_STATIC (init
) = 1;
953 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
954 TI provides information about the particular __class_type_info derivation,
955 which adds hint flags and TRAIL initializers to the type_info base. */
958 class_initializer (tinfo_s
*ti
, tree target
, tree trail
)
960 tree init
= tinfo_base_init (ti
, target
);
962 TREE_CHAIN (init
) = trail
;
963 init
= build_constructor_from_list (NULL_TREE
, init
);
964 TREE_CONSTANT (init
) = 1;
965 TREE_INVARIANT (init
) = 1;
966 TREE_STATIC (init
) = 1;
970 /* Returns true if the typeinfo for type should be placed in
971 the runtime library. */
974 typeinfo_in_lib_p (tree type
)
976 /* The typeinfo objects for `T*' and `const T*' are in the runtime
977 library for simple types T. */
978 if (TREE_CODE (type
) == POINTER_TYPE
979 && (cp_type_quals (TREE_TYPE (type
)) == TYPE_QUAL_CONST
980 || cp_type_quals (TREE_TYPE (type
)) == TYPE_UNQUALIFIED
))
981 type
= TREE_TYPE (type
);
983 switch (TREE_CODE (type
))
996 /* Generate the initializer for the type info describing TYPE. TK_INDEX is
997 the index of the descriptor in the tinfo_desc vector. */
1000 get_pseudo_ti_init (tree type
, unsigned tk_index
)
1002 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1004 gcc_assert (at_eof
);
1007 case TK_POINTER_MEMBER_TYPE
:
1008 return ptm_initializer (ti
, type
);
1010 case TK_POINTER_TYPE
:
1011 return ptr_initializer (ti
, type
);
1013 case TK_BUILTIN_TYPE
:
1014 case TK_ENUMERAL_TYPE
:
1015 case TK_FUNCTION_TYPE
:
1017 return generic_initializer (ti
, type
);
1020 return class_initializer (ti
, type
, NULL_TREE
);
1022 case TK_SI_CLASS_TYPE
:
1024 tree base_binfo
= BINFO_BASE_BINFO (TYPE_BINFO (type
), 0);
1025 tree tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1026 tree base_inits
= tree_cons (NULL_TREE
, tinfo
, NULL_TREE
);
1028 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1029 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1030 return class_initializer (ti
, type
, base_inits
);
1035 int hint
= ((CLASSTYPE_REPEATED_BASE_P (type
) << 0)
1036 | (CLASSTYPE_DIAMOND_SHAPED_P (type
) << 1));
1037 tree binfo
= TYPE_BINFO (type
);
1038 int nbases
= BINFO_N_BASE_BINFOS (binfo
);
1039 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1040 tree offset_type
= integer_types
[itk_long
];
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
);
1066 offset
= BINFO_OFFSET (base_binfo
);
1068 /* Combine offset and flags into one field. */
1069 offset
= fold_convert (offset_type
, offset
);
1070 offset
= fold_build2 (LSHIFT_EXPR
, offset_type
, offset
,
1071 build_int_cst (offset_type
, 8));
1072 offset
= fold_build2 (BIT_IOR_EXPR
, offset_type
, offset
,
1073 build_int_cst (offset_type
, 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"