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"
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
build_headof (tree
);
105 static tree
ifnonnull (tree
, tree
);
106 static tree
tinfo_name (tree
);
107 static tree
build_dynamic_cast_1 (tree
, tree
);
108 static tree
throw_bad_cast (void);
109 static tree
throw_bad_typeid (void);
110 static tree
get_tinfo_decl_dynamic (tree
);
111 static tree
get_tinfo_ptr (tree
);
112 static bool typeid_ok_p (void);
113 static int qualifier_flags (tree
);
114 static bool target_incomplete_p (tree
);
115 static tree
tinfo_base_init (tinfo_s
*, tree
);
116 static tree
generic_initializer (tinfo_s
*, tree
);
117 static tree
ptr_initializer (tinfo_s
*, tree
);
118 static tree
ptm_initializer (tinfo_s
*, tree
);
119 static tree
class_initializer (tinfo_s
*, tree
, tree
);
120 static void create_pseudo_type_info (int, const char *, ...);
121 static tree
get_pseudo_ti_init (tree
, unsigned);
122 static unsigned get_pseudo_ti_index (tree
);
123 static void create_tinfo_types (void);
124 static bool typeinfo_in_lib_p (tree
);
126 static int doing_runtime
= 0;
129 /* Declare language defined type_info type and a pointer to const
130 type_info. This is incomplete here, and will be completed when
131 the user #includes <typeinfo>. There are language defined
132 restrictions on what can be done until that is included. Create
133 the internal versions of the ABI types. */
136 init_rtti_processing (void)
140 push_namespace (std_identifier
);
141 type_info_type
= xref_tag (class_type
, get_identifier ("type_info"),
142 /*tag_scope=*/ts_current
, false);
144 const_type_info_type_node
145 = build_qualified_type (type_info_type
, TYPE_QUAL_CONST
);
146 type_info_ptr_type
= build_pointer_type (const_type_info_type_node
);
148 unemitted_tinfo_decls
= VEC_alloc (tree
, gc
, 124);
150 create_tinfo_types ();
153 /* Given the expression EXP of type `class *', return the head of the
154 object pointed to by EXP with type cv void*, if the class has any
155 virtual functions (TYPE_POLYMORPHIC_P), else just return the
159 build_headof (tree exp
)
161 tree type
= TREE_TYPE (exp
);
165 gcc_assert (TREE_CODE (type
) == POINTER_TYPE
);
166 type
= TREE_TYPE (type
);
168 if (!TYPE_POLYMORPHIC_P (type
))
171 /* We use this a couple of times below, protect it. */
172 exp
= save_expr (exp
);
174 /* The offset-to-top field is at index -2 from the vptr. */
175 index
= build_int_cst (NULL_TREE
,
176 -2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
);
178 offset
= build_vtbl_ref (build_indirect_ref (exp
, NULL
), index
);
180 type
= build_qualified_type (ptr_type_node
,
181 cp_type_quals (TREE_TYPE (exp
)));
182 return build2 (PLUS_EXPR
, type
, exp
,
183 convert_to_integer (ptrdiff_type_node
, offset
));
186 /* Get a bad_cast node for the program to throw...
188 See libstdc++/exception.cc for __throw_bad_cast */
191 throw_bad_cast (void)
193 tree fn
= get_identifier ("__cxa_bad_cast");
194 if (!get_global_value_if_present (fn
, &fn
))
195 fn
= push_throw_library_fn (fn
, build_function_type (ptr_type_node
,
198 return build_cxx_call (fn
, NULL_TREE
);
201 /* Return an expression for "__cxa_bad_typeid()". The expression
202 returned is an lvalue of type "const std::type_info". */
205 throw_bad_typeid (void)
207 tree fn
= get_identifier ("__cxa_bad_typeid");
208 if (!get_global_value_if_present (fn
, &fn
))
212 t
= build_reference_type (const_type_info_type_node
);
213 t
= build_function_type (t
, void_list_node
);
214 fn
= push_throw_library_fn (fn
, t
);
217 return build_cxx_call (fn
, NULL_TREE
);
220 /* Return an lvalue expression whose type is "const std::type_info"
221 and whose value indicates the type of the expression EXP. If EXP
222 is a reference to a polymorphic class, return the dynamic type;
223 otherwise return the static type of the expression. */
226 get_tinfo_decl_dynamic (tree exp
)
231 if (error_operand_p (exp
))
232 return error_mark_node
;
234 /* peel back references, so they match. */
235 type
= non_reference (TREE_TYPE (exp
));
237 /* Peel off cv qualifiers. */
238 type
= TYPE_MAIN_VARIANT (type
);
240 if (!VOID_TYPE_P (type
))
241 type
= complete_type_or_else (type
, exp
);
244 return error_mark_node
;
246 /* If exp is a reference to polymorphic type, get the real type_info. */
247 if (TYPE_POLYMORPHIC_P (type
) && ! resolves_to_fixed_type_p (exp
, 0))
249 /* build reference to type_info from vtable. */
252 /* The RTTI information is at index -1. */
253 index
= build_int_cst (NULL_TREE
,
254 -1 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
);
255 t
= build_vtbl_ref (exp
, index
);
256 t
= convert (type_info_ptr_type
, t
);
259 /* Otherwise return the type_info for the static type of the expr. */
260 t
= get_tinfo_ptr (TYPE_MAIN_VARIANT (type
));
262 return build_indirect_ref (t
, NULL
);
270 error ("cannot use typeid with -fno-rtti");
274 if (!COMPLETE_TYPE_P (const_type_info_type_node
))
276 error ("must #include <typeinfo> before using typeid");
283 /* Return an expression for "typeid(EXP)". The expression returned is
284 an lvalue of type "const std::type_info". */
287 build_typeid (tree exp
)
289 tree cond
= NULL_TREE
;
292 if (exp
== error_mark_node
|| !typeid_ok_p ())
293 return error_mark_node
;
295 if (processing_template_decl
)
296 return build_min (TYPEID_EXPR
, const_type_info_type_node
, exp
);
298 if (TREE_CODE (exp
) == INDIRECT_REF
299 && TREE_CODE (TREE_TYPE (TREE_OPERAND (exp
, 0))) == POINTER_TYPE
300 && TYPE_POLYMORPHIC_P (TREE_TYPE (exp
))
301 && ! resolves_to_fixed_type_p (exp
, &nonnull
)
304 exp
= stabilize_reference (exp
);
305 cond
= cp_convert (boolean_type_node
, TREE_OPERAND (exp
, 0));
308 exp
= get_tinfo_decl_dynamic (exp
);
310 if (exp
== error_mark_node
)
311 return error_mark_node
;
315 tree bad
= throw_bad_typeid ();
317 exp
= build3 (COND_EXPR
, TREE_TYPE (exp
), cond
, exp
, bad
);
323 /* Generate the NTBS name of a type. */
325 tinfo_name (tree type
)
330 name
= mangle_type_string (type
);
331 name_string
= fix_string_type (build_string (strlen (name
) + 1, name
));
335 /* Return a VAR_DECL for the internal ABI defined type_info object for
336 TYPE. You must arrange that the decl is mark_used, if actually use
337 it --- decls in vtables are only used if the vtable is output. */
340 get_tinfo_decl (tree type
)
345 if (variably_modified_type_p (type
, /*fn=*/NULL_TREE
))
347 error ("cannot create type information for type %qT because "
348 "it involves types of variable size",
350 return error_mark_node
;
353 if (TREE_CODE (type
) == METHOD_TYPE
)
354 type
= build_function_type (TREE_TYPE (type
),
355 TREE_CHAIN (TYPE_ARG_TYPES (type
)));
357 /* For a class type, the variable is cached in the type node
359 if (CLASS_TYPE_P (type
))
361 d
= CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
));
366 name
= mangle_typeinfo_for_type (type
);
368 d
= IDENTIFIER_GLOBAL_VALUE (name
);
371 int ix
= get_pseudo_ti_index (type
);
372 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, ix
);
374 d
= build_lang_decl (VAR_DECL
, name
, ti
->type
);
375 SET_DECL_ASSEMBLER_NAME (d
, name
);
376 /* Remember the type it is for. */
377 TREE_TYPE (name
) = type
;
378 DECL_TINFO_P (d
) = 1;
379 DECL_ARTIFICIAL (d
) = 1;
380 DECL_IGNORED_P (d
) = 1;
381 TREE_READONLY (d
) = 1;
383 /* Mark the variable as undefined -- but remember that we can
384 define it later if we need to do so. */
385 DECL_EXTERNAL (d
) = 1;
386 DECL_NOT_REALLY_EXTERN (d
) = 1;
387 if (CLASS_TYPE_P (type
))
388 CLASSTYPE_TYPEINFO_VAR (TYPE_MAIN_VARIANT (type
)) = d
;
389 set_linkage_according_to_type (type
, d
);
390 pushdecl_top_level_and_finish (d
, NULL_TREE
);
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 (!VOID_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 /* T shall be a pointer or reference to a complete class type, or
467 `pointer to cv void''. */
471 if (TREE_CODE (TREE_TYPE (type
)) == VOID_TYPE
)
475 if (! IS_AGGR_TYPE (TREE_TYPE (type
)))
477 errstr
= "target is not pointer or reference to class";
480 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type
))))
482 errstr
= "target is not pointer or reference to complete type";
488 errstr
= "target is not pointer or reference";
492 if (tc
== POINTER_TYPE
)
494 /* If T is a pointer type, v shall be an rvalue of a pointer to
495 complete class type, and the result is an rvalue of type T. */
497 if (TREE_CODE (exprtype
) != POINTER_TYPE
)
499 errstr
= "source is not a pointer";
502 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
504 errstr
= "source is not a pointer to class";
507 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
509 errstr
= "source is a pointer to incomplete type";
515 exprtype
= build_reference_type (exprtype
);
517 /* T is a reference type, v shall be an lvalue of a complete class
518 type, and the result is an lvalue of the type referred to by T. */
520 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
522 errstr
= "source is not of class type";
525 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
527 errstr
= "source is of incomplete class type";
531 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
532 expr
= convert_to_reference (exprtype
, expr
, CONV_IMPLICIT
,
533 LOOKUP_NORMAL
, NULL_TREE
);
536 /* The dynamic_cast operator shall not cast away constness. */
537 if (!at_least_as_qualified_p (TREE_TYPE (type
),
538 TREE_TYPE (exprtype
)))
540 errstr
= "conversion casts away constness";
544 /* If *type is an unambiguous accessible base class of *exprtype,
545 convert statically. */
549 binfo
= lookup_base (TREE_TYPE (exprtype
), TREE_TYPE (type
),
554 expr
= build_base_path (PLUS_EXPR
, convert_from_reference (expr
),
556 if (TREE_CODE (exprtype
) == POINTER_TYPE
)
557 expr
= rvalue (expr
);
562 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
563 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype
)))
566 /* if TYPE is `void *', return pointer to complete object. */
567 if (tc
== POINTER_TYPE
&& VOID_TYPE_P (TREE_TYPE (type
)))
569 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
570 if (TREE_CODE (expr
) == ADDR_EXPR
571 && TREE_CODE (TREE_OPERAND (expr
, 0)) == VAR_DECL
572 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == RECORD_TYPE
)
573 return build1 (NOP_EXPR
, type
, expr
);
575 /* Since expr is used twice below, save it. */
576 expr
= save_expr (expr
);
578 expr1
= build_headof (expr
);
579 if (TREE_TYPE (expr1
) != type
)
580 expr1
= build1 (NOP_EXPR
, type
, expr1
);
581 return ifnonnull (expr
, expr1
);
586 tree result
, td2
, td3
, elems
;
587 tree static_type
, target_type
, boff
;
589 /* If we got here, we can't convert statically. Therefore,
590 dynamic_cast<D&>(b) (b an object) cannot succeed. */
591 if (tc
== REFERENCE_TYPE
)
593 if (TREE_CODE (old_expr
) == VAR_DECL
594 && TREE_CODE (TREE_TYPE (old_expr
)) == RECORD_TYPE
)
596 tree expr
= throw_bad_cast ();
597 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
599 /* Bash it to the expected type. */
600 TREE_TYPE (expr
) = type
;
604 /* Ditto for dynamic_cast<D*>(&b). */
605 else if (TREE_CODE (expr
) == ADDR_EXPR
)
607 tree op
= TREE_OPERAND (expr
, 0);
608 if (TREE_CODE (op
) == VAR_DECL
609 && TREE_CODE (TREE_TYPE (op
)) == RECORD_TYPE
)
611 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
613 retval
= build_int_cst (type
, 0);
618 target_type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
619 static_type
= TYPE_MAIN_VARIANT (TREE_TYPE (exprtype
));
620 td2
= get_tinfo_decl (target_type
);
622 td2
= build_unary_op (ADDR_EXPR
, td2
, 0);
623 td3
= get_tinfo_decl (static_type
);
625 td3
= build_unary_op (ADDR_EXPR
, td3
, 0);
627 /* Determine how T and V are related. */
628 boff
= dcast_base_hint (static_type
, target_type
);
630 /* Since expr is used twice below, save it. */
631 expr
= save_expr (expr
);
634 if (tc
== REFERENCE_TYPE
)
635 expr1
= build_unary_op (ADDR_EXPR
, expr1
, 0);
638 (NULL_TREE
, expr1
, tree_cons
639 (NULL_TREE
, td3
, tree_cons
640 (NULL_TREE
, td2
, tree_cons
641 (NULL_TREE
, boff
, NULL_TREE
))));
643 dcast_fn
= dynamic_cast_node
;
651 push_nested_namespace (ns
);
652 tinfo_ptr
= xref_tag (class_type
,
653 get_identifier ("__class_type_info"),
654 /*tag_scope=*/ts_current
, false);
656 tinfo_ptr
= build_pointer_type
657 (build_qualified_type
658 (tinfo_ptr
, TYPE_QUAL_CONST
));
659 name
= "__dynamic_cast";
661 (NULL_TREE
, const_ptr_type_node
, tree_cons
662 (NULL_TREE
, tinfo_ptr
, tree_cons
663 (NULL_TREE
, tinfo_ptr
, tree_cons
664 (NULL_TREE
, ptrdiff_type_node
, void_list_node
))));
665 tmp
= build_function_type (ptr_type_node
, tmp
);
666 dcast_fn
= build_library_fn_ptr (name
, tmp
);
667 DECL_IS_PURE (dcast_fn
) = 1;
668 pop_nested_namespace (ns
);
669 dynamic_cast_node
= dcast_fn
;
671 result
= build_cxx_call (dcast_fn
, elems
);
673 if (tc
== REFERENCE_TYPE
)
675 tree bad
= throw_bad_cast ();
677 result
= save_expr (result
);
678 return build3 (COND_EXPR
, type
, result
, result
, bad
);
681 /* Now back to the type we want from a void*. */
682 result
= cp_convert (type
, result
);
683 return ifnonnull (expr
, result
);
687 errstr
= "source type is not polymorphic";
690 error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
691 expr
, exprtype
, type
, errstr
);
692 return error_mark_node
;
696 build_dynamic_cast (tree type
, tree expr
)
698 if (type
== error_mark_node
|| expr
== error_mark_node
)
699 return error_mark_node
;
701 if (processing_template_decl
)
703 expr
= build_min (DYNAMIC_CAST_EXPR
, type
, expr
);
704 TREE_SIDE_EFFECTS (expr
) = 1;
709 return convert_from_reference (build_dynamic_cast_1 (type
, expr
));
712 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
715 qualifier_flags (tree type
)
718 int quals
= cp_type_quals (type
);
720 if (quals
& TYPE_QUAL_CONST
)
722 if (quals
& TYPE_QUAL_VOLATILE
)
724 if (quals
& TYPE_QUAL_RESTRICT
)
729 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
730 contains a pointer to member of an incomplete class. */
733 target_incomplete_p (tree type
)
736 if (TYPE_PTRMEM_P (type
))
738 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)))
740 type
= TYPE_PTRMEM_POINTED_TO_TYPE (type
);
742 else if (TREE_CODE (type
) == POINTER_TYPE
)
743 type
= TREE_TYPE (type
);
745 return !COMPLETE_OR_VOID_TYPE_P (type
);
748 /* Returns true if TYPE involves an incomplete class type; in that
749 case, typeinfo variables for TYPE should be emitted with internal
753 involves_incomplete_p (tree type
)
755 switch (TREE_CODE (type
))
758 return target_incomplete_p (TREE_TYPE (type
));
763 (target_incomplete_p (TYPE_PTRMEM_POINTED_TO_TYPE (type
))
764 || !COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)));
767 if (TYPE_PTRMEMFUNC_P (type
))
771 if (!COMPLETE_TYPE_P (type
))
775 /* All other types do not involve incomplete class types. */
780 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
781 is the vtable pointer and NTBS name. The NTBS name is emitted as a
782 comdat const char array, so it becomes a unique key for the type. Generate
783 and emit that VAR_DECL here. (We can't always emit the type_info itself
784 as comdat, because of pointers to incomplete.) */
787 tinfo_base_init (tinfo_s
*ti
, tree target
)
789 tree init
= NULL_TREE
;
796 /* Generate the NTBS array variable. */
797 tree name_type
= build_cplus_array_type
798 (build_qualified_type (char_type_node
, TYPE_QUAL_CONST
),
800 tree name_string
= tinfo_name (target
);
802 /* Determine the name of the variable -- and remember with which
803 type it is associated. */
804 name_name
= mangle_typeinfo_string_for_type (target
);
805 TREE_TYPE (name_name
) = target
;
807 name_decl
= build_lang_decl (VAR_DECL
, name_name
, name_type
);
808 SET_DECL_ASSEMBLER_NAME (name_decl
, name_name
);
809 DECL_ARTIFICIAL (name_decl
) = 1;
810 DECL_IGNORED_P (name_decl
) = 1;
811 TREE_READONLY (name_decl
) = 1;
812 TREE_STATIC (name_decl
) = 1;
813 DECL_EXTERNAL (name_decl
) = 0;
814 DECL_TINFO_P (name_decl
) = 1;
815 set_linkage_according_to_type (target
, name_decl
);
816 import_export_decl (name_decl
);
817 DECL_INITIAL (name_decl
) = name_string
;
818 mark_used (name_decl
);
819 pushdecl_top_level_and_finish (name_decl
, name_string
);
822 vtable_ptr
= ti
->vtable
;
826 push_nested_namespace (abi_node
);
827 real_type
= xref_tag (class_type
, ti
->name
,
828 /*tag_scope=*/ts_current
, false);
829 pop_nested_namespace (abi_node
);
831 if (!COMPLETE_TYPE_P (real_type
))
833 /* We never saw a definition of this type, so we need to
834 tell the compiler that this is an exported class, as
835 indeed all of the __*_type_info classes are. */
836 SET_CLASSTYPE_INTERFACE_KNOWN (real_type
);
837 CLASSTYPE_INTERFACE_ONLY (real_type
) = 1;
840 vtable_ptr
= get_vtable_decl (real_type
, /*complete=*/1);
841 vtable_ptr
= build_unary_op (ADDR_EXPR
, vtable_ptr
, 0);
843 /* We need to point into the middle of the vtable. */
845 (PLUS_EXPR
, TREE_TYPE (vtable_ptr
), vtable_ptr
,
846 size_binop (MULT_EXPR
,
847 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
),
848 TYPE_SIZE_UNIT (vtable_entry_type
)));
850 ti
->vtable
= vtable_ptr
;
853 init
= tree_cons (NULL_TREE
, vtable_ptr
, init
);
855 init
= tree_cons (NULL_TREE
, decay_conversion (name_decl
), init
);
857 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
858 TREE_CONSTANT (init
) = 1;
859 TREE_INVARIANT (init
) = 1;
860 TREE_STATIC (init
) = 1;
861 init
= tree_cons (NULL_TREE
, init
, NULL_TREE
);
866 /* Return the CONSTRUCTOR expr for a type_info of TYPE. TI provides the
867 information about the particular type_info derivation, which adds no
868 additional fields to the type_info base. */
871 generic_initializer (tinfo_s
*ti
, tree target
)
873 tree init
= tinfo_base_init (ti
, target
);
875 init
= build_constructor_from_list (NULL_TREE
, init
);
876 TREE_CONSTANT (init
) = 1;
877 TREE_INVARIANT (init
) = 1;
878 TREE_STATIC (init
) = 1;
882 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
883 TI provides information about the particular type_info derivation,
884 which adds target type and qualifier flags members to the type_info base. */
887 ptr_initializer (tinfo_s
*ti
, tree target
)
889 tree init
= tinfo_base_init (ti
, target
);
890 tree to
= TREE_TYPE (target
);
891 int flags
= qualifier_flags (to
);
892 bool incomplete
= target_incomplete_p (to
);
896 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
897 init
= tree_cons (NULL_TREE
,
898 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
901 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
902 TREE_CONSTANT (init
) = 1;
903 TREE_INVARIANT (init
) = 1;
904 TREE_STATIC (init
) = 1;
908 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
909 TI provides information about the particular type_info derivation,
910 which adds class, target type and qualifier flags members to the type_info
914 ptm_initializer (tinfo_s
*ti
, tree target
)
916 tree init
= tinfo_base_init (ti
, target
);
917 tree to
= TYPE_PTRMEM_POINTED_TO_TYPE (target
);
918 tree klass
= TYPE_PTRMEM_CLASS_TYPE (target
);
919 int flags
= qualifier_flags (to
);
920 bool incomplete
= target_incomplete_p (to
);
924 if (!COMPLETE_TYPE_P (klass
))
926 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
927 init
= tree_cons (NULL_TREE
,
928 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
930 init
= tree_cons (NULL_TREE
,
931 get_tinfo_ptr (klass
),
934 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
935 TREE_CONSTANT (init
) = 1;
936 TREE_INVARIANT (init
) = 1;
937 TREE_STATIC (init
) = 1;
941 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
942 TI provides information about the particular __class_type_info derivation,
943 which adds hint flags and TRAIL initializers to the type_info base. */
946 class_initializer (tinfo_s
*ti
, tree target
, tree trail
)
948 tree init
= tinfo_base_init (ti
, target
);
950 TREE_CHAIN (init
) = trail
;
951 init
= build_constructor_from_list (NULL_TREE
, init
);
952 TREE_CONSTANT (init
) = 1;
953 TREE_INVARIANT (init
) = 1;
954 TREE_STATIC (init
) = 1;
958 /* Returns true if the typeinfo for type should be placed in
959 the runtime library. */
962 typeinfo_in_lib_p (tree type
)
964 /* The typeinfo objects for `T*' and `const T*' are in the runtime
965 library for simple types T. */
966 if (TREE_CODE (type
) == POINTER_TYPE
967 && (cp_type_quals (TREE_TYPE (type
)) == TYPE_QUAL_CONST
968 || cp_type_quals (TREE_TYPE (type
)) == TYPE_UNQUALIFIED
))
969 type
= TREE_TYPE (type
);
971 switch (TREE_CODE (type
))
985 /* Generate the initializer for the type info describing TYPE. TK_INDEX is
986 the index of the descriptor in the tinfo_desc vector. */
989 get_pseudo_ti_init (tree type
, unsigned tk_index
)
991 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
996 case TK_POINTER_MEMBER_TYPE
:
997 return ptm_initializer (ti
, type
);
999 case TK_POINTER_TYPE
:
1000 return ptr_initializer (ti
, type
);
1002 case TK_BUILTIN_TYPE
:
1003 case TK_ENUMERAL_TYPE
:
1004 case TK_FUNCTION_TYPE
:
1006 return generic_initializer (ti
, type
);
1009 return class_initializer (ti
, type
, NULL_TREE
);
1011 case TK_SI_CLASS_TYPE
:
1013 tree base_binfo
= BINFO_BASE_BINFO (TYPE_BINFO (type
), 0);
1014 tree tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1015 tree base_inits
= tree_cons (NULL_TREE
, tinfo
, NULL_TREE
);
1017 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1018 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1019 return class_initializer (ti
, type
, base_inits
);
1024 int hint
= ((CLASSTYPE_REPEATED_BASE_P (type
) << 0)
1025 | (CLASSTYPE_DIAMOND_SHAPED_P (type
) << 1));
1026 tree binfo
= TYPE_BINFO (type
);
1027 int nbases
= BINFO_N_BASE_BINFOS (binfo
);
1028 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1029 tree base_inits
= NULL_TREE
;
1032 gcc_assert (tk_index
>= TK_FIXED
);
1034 /* Generate the base information initializer. */
1035 for (ix
= nbases
; ix
--;)
1037 tree base_binfo
= BINFO_BASE_BINFO (binfo
, ix
);
1038 tree base_init
= NULL_TREE
;
1043 if (VEC_index (tree
, base_accesses
, ix
) == access_public_node
)
1045 tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1046 if (BINFO_VIRTUAL_P (base_binfo
))
1048 /* We store the vtable offset at which the virtual
1049 base offset can be found. */
1050 offset
= BINFO_VPTR_FIELD (base_binfo
);
1051 offset
= convert (sizetype
, offset
);
1055 offset
= BINFO_OFFSET (base_binfo
);
1057 /* Combine offset and flags into one field. */
1058 offset
= cp_build_binary_op (LSHIFT_EXPR
, offset
,
1059 build_int_cst (NULL_TREE
, 8));
1060 offset
= cp_build_binary_op (BIT_IOR_EXPR
, offset
,
1061 build_int_cst (NULL_TREE
, flags
));
1062 base_init
= tree_cons (NULL_TREE
, offset
, base_init
);
1063 base_init
= tree_cons (NULL_TREE
, tinfo
, base_init
);
1064 base_init
= build_constructor_from_list (NULL_TREE
, base_init
);
1065 base_inits
= tree_cons (NULL_TREE
, base_init
, base_inits
);
1067 base_inits
= build_constructor_from_list (NULL_TREE
, base_inits
);
1068 base_inits
= tree_cons (NULL_TREE
, base_inits
, NULL_TREE
);
1069 /* Prepend the number of bases. */
1070 base_inits
= tree_cons (NULL_TREE
,
1071 build_int_cst (NULL_TREE
, nbases
),
1073 /* Prepend the hint flags. */
1074 base_inits
= tree_cons (NULL_TREE
,
1075 build_int_cst (NULL_TREE
, hint
),
1078 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1079 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1080 return class_initializer (ti
, type
, base_inits
);
1085 /* Generate the RECORD_TYPE containing the data layout of a type_info
1086 derivative as used by the runtime. This layout must be consistent with
1087 that defined in the runtime support. Also generate the VAR_DECL for the
1088 type's vtable. We explicitly manage the vtable member, and name it for
1089 real type as used in the runtime. The RECORD type has a different name,
1090 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1091 is the generated type and TINFO_VTABLE_NAME is the name of the
1092 vtable. We have to delay generating the VAR_DECL of the vtable
1093 until the end of the translation, when we'll have seen the library
1094 definition, if there was one.
1096 REAL_NAME is the runtime's name of the type. Trailing arguments are
1097 additional FIELD_DECL's for the structure. The final argument must be
1101 create_pseudo_type_info (int tk
, const char *real_name
, ...)
1110 va_start (ap
, real_name
);
1112 /* Generate the pseudo type name. */
1113 pseudo_name
= alloca (strlen (real_name
) + 30);
1114 strcpy (pseudo_name
, real_name
);
1115 strcat (pseudo_name
, "_pseudo");
1117 sprintf (pseudo_name
+ strlen (pseudo_name
), "%d", tk
- TK_FIXED
);
1119 /* First field is the pseudo type_info base class. */
1120 fields
= build_decl (FIELD_DECL
, NULL_TREE
,
1121 VEC_index (tinfo_s
, tinfo_descs
,
1122 TK_TYPE_INFO_TYPE
)->type
);
1124 /* Now add the derived fields. */
1125 while ((field_decl
= va_arg (ap
, tree
)))
1127 TREE_CHAIN (field_decl
) = fields
;
1128 fields
= field_decl
;
1131 /* Create the pseudo type. */
1132 pseudo_type
= make_aggr_type (RECORD_TYPE
);
1133 finish_builtin_struct (pseudo_type
, pseudo_name
, fields
, NULL_TREE
);
1134 CLASSTYPE_AS_BASE (pseudo_type
) = pseudo_type
;
1136 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk
);
1137 ti
->type
= cp_build_qualified_type (pseudo_type
, TYPE_QUAL_CONST
);
1138 ti
->name
= get_identifier (real_name
);
1139 ti
->vtable
= NULL_TREE
;
1144 /* Return the index of a pseudo type info type node used to describe
1145 TYPE. TYPE must be a complete type (or cv void), except at the end
1146 of the translation unit. */
1149 get_pseudo_ti_index (tree type
)
1153 switch (TREE_CODE (type
))
1156 ix
= TK_POINTER_MEMBER_TYPE
;
1160 ix
= TK_POINTER_TYPE
;
1164 ix
= TK_ENUMERAL_TYPE
;
1168 ix
= TK_FUNCTION_TYPE
;
1177 if (TYPE_PTRMEMFUNC_P (type
))
1179 ix
= TK_POINTER_MEMBER_TYPE
;
1182 else if (!COMPLETE_TYPE_P (type
))
1185 cxx_incomplete_type_error (NULL_TREE
, type
);
1189 else if (!BINFO_N_BASE_BINFOS (TYPE_BINFO (type
)))
1196 tree binfo
= TYPE_BINFO (type
);
1197 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1198 tree base_binfo
= BINFO_BASE_BINFO (binfo
, 0);
1199 int num_bases
= BINFO_N_BASE_BINFOS (binfo
);
1202 && VEC_index (tree
, base_accesses
, 0) == access_public_node
1203 && !BINFO_VIRTUAL_P (base_binfo
)
1204 && integer_zerop (BINFO_OFFSET (base_binfo
)))
1206 /* single non-virtual public. */
1207 ix
= TK_SI_CLASS_TYPE
;
1213 tree array_domain
, base_array
;
1215 ix
= TK_FIXED
+ num_bases
;
1216 if (VEC_length (tinfo_s
, tinfo_descs
) <= ix
)
1218 /* too short, extend. */
1219 unsigned len
= VEC_length (tinfo_s
, tinfo_descs
);
1221 VEC_safe_grow (tinfo_s
, gc
, tinfo_descs
, ix
+ 1);
1222 while (VEC_iterate (tinfo_s
, tinfo_descs
, len
++, ti
))
1223 ti
->type
= ti
->vtable
= ti
->name
= NULL_TREE
;
1225 else if (VEC_index (tinfo_s
, tinfo_descs
, ix
)->type
)
1226 /* already created. */
1229 /* Create the array of __base_class_type_info entries.
1230 G++ 3.2 allocated an array that had one too many
1231 entries, and then filled that extra entries with
1233 if (abi_version_at_least (2))
1234 array_domain
= build_index_type (size_int (num_bases
- 1));
1236 array_domain
= build_index_type (size_int (num_bases
));
1238 build_array_type (VEC_index (tinfo_s
, tinfo_descs
,
1239 TK_BASE_TYPE
)->type
,
1242 push_nested_namespace (abi_node
);
1243 create_pseudo_type_info
1244 (ix
, "__vmi_class_type_info",
1245 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1246 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1247 build_decl (FIELD_DECL
, NULL_TREE
, base_array
),
1249 pop_nested_namespace (abi_node
);
1254 ix
= TK_BUILTIN_TYPE
;
1260 /* Make sure the required builtin types exist for generating the type_info
1261 variable definitions. */
1264 create_tinfo_types (void)
1268 gcc_assert (!tinfo_descs
);
1270 VEC_safe_grow (tinfo_s
, gc
, tinfo_descs
, TK_FIXED
);
1272 push_nested_namespace (abi_node
);
1274 /* Create the internal type_info structure. This is used as a base for
1275 the other structures. */
1279 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_ptr_type_node
);
1282 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_string_type_node
);
1283 TREE_CHAIN (field
) = fields
;
1286 ti
= VEC_index (tinfo_s
, tinfo_descs
, TK_TYPE_INFO_TYPE
);
1287 ti
->type
= make_aggr_type (RECORD_TYPE
);
1288 ti
->vtable
= NULL_TREE
;
1289 ti
->name
= NULL_TREE
;
1290 finish_builtin_struct (ti
->type
, "__type_info_pseudo",
1292 TYPE_HAS_CONSTRUCTOR (ti
->type
) = 1;
1295 /* Fundamental type_info */
1296 create_pseudo_type_info (TK_BUILTIN_TYPE
, "__fundamental_type_info", NULL
);
1298 /* Array, function and enum type_info. No additional fields. */
1299 create_pseudo_type_info (TK_ARRAY_TYPE
, "__array_type_info", NULL
);
1300 create_pseudo_type_info (TK_FUNCTION_TYPE
, "__function_type_info", NULL
);
1301 create_pseudo_type_info (TK_ENUMERAL_TYPE
, "__enum_type_info", NULL
);
1303 /* Class type_info. No additional fields. */
1304 create_pseudo_type_info (TK_CLASS_TYPE
, "__class_type_info", NULL
);
1306 /* Single public non-virtual base class. Add pointer to base class.
1307 This is really a descendant of __class_type_info. */
1308 create_pseudo_type_info (TK_SI_CLASS_TYPE
, "__si_class_type_info",
1309 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1312 /* Base class internal helper. Pointer to base type, offset to base,
1317 field
= build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
);
1320 field
= build_decl (FIELD_DECL
, NULL_TREE
, integer_types
[itk_long
]);
1321 TREE_CHAIN (field
) = fields
;
1324 ti
= VEC_index (tinfo_s
, tinfo_descs
, TK_BASE_TYPE
);
1326 ti
->type
= make_aggr_type (RECORD_TYPE
);
1327 ti
->vtable
= NULL_TREE
;
1328 ti
->name
= NULL_TREE
;
1329 finish_builtin_struct (ti
->type
, "__base_class_type_info_pseudo",
1331 TYPE_HAS_CONSTRUCTOR (ti
->type
) = 1;
1334 /* Pointer type_info. Adds two fields, qualification mask
1335 and pointer to the pointed to type. This is really a descendant of
1336 __pbase_type_info. */
1337 create_pseudo_type_info (TK_POINTER_TYPE
, "__pointer_type_info",
1338 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1339 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1342 /* Pointer to member data type_info. Add qualifications flags,
1343 pointer to the member's type info and pointer to the class.
1344 This is really a descendant of __pbase_type_info. */
1345 create_pseudo_type_info (TK_POINTER_MEMBER_TYPE
,
1346 "__pointer_to_member_type_info",
1347 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1348 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1349 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1352 pop_nested_namespace (abi_node
);
1355 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1356 support. Generating them here guarantees consistency with the other
1357 structures. We use the following heuristic to determine when the runtime
1358 is being generated. If std::__fundamental_type_info is defined, and its
1359 destructor is defined, then the runtime is being built. */
1362 emit_support_tinfos (void)
1364 static tree
*const fundamentals
[] =
1369 &char_type_node
, &signed_char_type_node
, &unsigned_char_type_node
,
1370 &short_integer_type_node
, &short_unsigned_type_node
,
1371 &integer_type_node
, &unsigned_type_node
,
1372 &long_integer_type_node
, &long_unsigned_type_node
,
1373 &long_long_integer_type_node
, &long_long_unsigned_type_node
,
1374 &float_type_node
, &double_type_node
, &long_double_type_node
,
1378 tree bltn_type
, dtor
;
1380 push_nested_namespace (abi_node
);
1381 bltn_type
= xref_tag (class_type
,
1382 get_identifier ("__fundamental_type_info"),
1383 /*tag_scope=*/ts_current
, false);
1384 pop_nested_namespace (abi_node
);
1385 if (!COMPLETE_TYPE_P (bltn_type
))
1387 dtor
= CLASSTYPE_DESTRUCTORS (bltn_type
);
1388 if (!dtor
|| DECL_EXTERNAL (dtor
))
1391 for (ix
= 0; fundamentals
[ix
]; ix
++)
1393 tree bltn
= *fundamentals
[ix
];
1398 types
[1] = build_pointer_type (bltn
);
1399 types
[2] = build_pointer_type (build_qualified_type (bltn
,
1402 for (i
= 0; i
< 3; ++i
)
1406 tinfo
= get_tinfo_decl (types
[i
]);
1407 TREE_USED (tinfo
) = 1;
1408 mark_needed (tinfo
);
1409 /* The C++ ABI requires that these objects be COMDAT. But,
1410 On systems without weak symbols, initialized COMDAT
1411 objects are emitted with internal linkage. (See
1412 comdat_linkage for details.) Since we want these objects
1413 to have external linkage so that copies do not have to be
1414 emitted in code outside the runtime library, we make them
1418 gcc_assert (TREE_PUBLIC (tinfo
) && !DECL_COMDAT (tinfo
));
1419 DECL_INTERFACE_KNOWN (tinfo
) = 1;
1425 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1426 tinfo decl. Determine whether it needs emitting, and if so
1427 generate the initializer. */
1430 emit_tinfo_decl (tree decl
)
1432 tree type
= TREE_TYPE (DECL_NAME (decl
));
1433 int in_library
= typeinfo_in_lib_p (type
);
1435 gcc_assert (DECL_TINFO_P (decl
));
1440 DECL_EXTERNAL (decl
) = 0;
1443 /* If we're not in the runtime, then DECL (which is already
1444 DECL_EXTERNAL) will not be defined here. */
1445 DECL_INTERFACE_KNOWN (decl
) = 1;
1449 else if (involves_incomplete_p (type
))
1451 if (!decl_needed_p (decl
))
1453 /* If TYPE involves an incomplete class type, then the typeinfo
1454 object will be emitted with internal linkage. There is no
1455 way to know whether or not types are incomplete until the end
1456 of the compilation, so this determination must be deferred
1457 until this point. */
1458 TREE_PUBLIC (decl
) = 0;
1459 DECL_EXTERNAL (decl
) = 0;
1460 DECL_INTERFACE_KNOWN (decl
) = 1;
1463 import_export_decl (decl
);
1464 if (DECL_NOT_REALLY_EXTERN (decl
) && decl_needed_p (decl
))
1468 DECL_EXTERNAL (decl
) = 0;
1469 init
= get_pseudo_ti_init (type
, get_pseudo_ti_index (type
));
1470 DECL_INITIAL (decl
) = init
;
1472 finish_decl (decl
, init
, NULL_TREE
);
1479 #include "gt-cp-rtti.h"