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 (exp
== error_mark_node
)
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 (COMPLETE_TYPE_P (type
)
346 && TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
348 error ("cannot create type information for type %qT because "
349 "its size is variable",
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 (!VOID_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 /* T shall be a pointer or reference to a complete class type, or
468 `pointer to cv void''. */
472 if (TREE_CODE (TREE_TYPE (type
)) == VOID_TYPE
)
476 if (! IS_AGGR_TYPE (TREE_TYPE (type
)))
478 errstr
= "target is not pointer or reference to class";
481 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type
))))
483 errstr
= "target is not pointer or reference to complete type";
489 errstr
= "target is not pointer or reference";
493 if (tc
== POINTER_TYPE
)
495 /* If T is a pointer type, v shall be an rvalue of a pointer to
496 complete class type, and the result is an rvalue of type T. */
498 if (TREE_CODE (exprtype
) != POINTER_TYPE
)
500 errstr
= "source is not a pointer";
503 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
505 errstr
= "source is not a pointer to class";
508 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
510 errstr
= "source is a pointer to incomplete type";
516 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
517 exprtype
= build_reference_type (exprtype
);
518 expr
= convert_to_reference (exprtype
, expr
, CONV_IMPLICIT
,
519 LOOKUP_NORMAL
, NULL_TREE
);
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";
537 /* The dynamic_cast operator shall not cast away constness. */
538 if (!at_least_as_qualified_p (TREE_TYPE (type
),
539 TREE_TYPE (exprtype
)))
541 errstr
= "conversion casts away constness";
545 /* If *type is an unambiguous accessible base class of *exprtype,
546 convert statically. */
550 binfo
= lookup_base (TREE_TYPE (exprtype
), TREE_TYPE (type
),
555 expr
= build_base_path (PLUS_EXPR
, convert_from_reference (expr
),
557 if (TREE_CODE (exprtype
) == POINTER_TYPE
)
558 expr
= rvalue (expr
);
563 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
564 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype
)))
567 /* if TYPE is `void *', return pointer to complete object. */
568 if (tc
== POINTER_TYPE
&& VOID_TYPE_P (TREE_TYPE (type
)))
570 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
571 if (TREE_CODE (expr
) == ADDR_EXPR
572 && TREE_CODE (TREE_OPERAND (expr
, 0)) == VAR_DECL
573 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == RECORD_TYPE
)
574 return build1 (NOP_EXPR
, type
, expr
);
576 /* Since expr is used twice below, save it. */
577 expr
= save_expr (expr
);
579 expr1
= build_headof (expr
);
580 if (TREE_TYPE (expr1
) != type
)
581 expr1
= build1 (NOP_EXPR
, type
, expr1
);
582 return ifnonnull (expr
, expr1
);
587 tree result
, td2
, td3
, elems
;
588 tree static_type
, target_type
, boff
;
590 /* If we got here, we can't convert statically. Therefore,
591 dynamic_cast<D&>(b) (b an object) cannot succeed. */
592 if (tc
== REFERENCE_TYPE
)
594 if (TREE_CODE (old_expr
) == VAR_DECL
595 && TREE_CODE (TREE_TYPE (old_expr
)) == RECORD_TYPE
)
597 tree expr
= throw_bad_cast ();
598 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
600 /* Bash it to the expected type. */
601 TREE_TYPE (expr
) = type
;
605 /* Ditto for dynamic_cast<D*>(&b). */
606 else if (TREE_CODE (expr
) == ADDR_EXPR
)
608 tree op
= TREE_OPERAND (expr
, 0);
609 if (TREE_CODE (op
) == VAR_DECL
610 && TREE_CODE (TREE_TYPE (op
)) == RECORD_TYPE
)
612 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
614 retval
= build_int_cst (type
, 0);
619 target_type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
620 static_type
= TYPE_MAIN_VARIANT (TREE_TYPE (exprtype
));
621 td2
= get_tinfo_decl (target_type
);
623 td2
= build_unary_op (ADDR_EXPR
, td2
, 0);
624 td3
= get_tinfo_decl (static_type
);
626 td3
= build_unary_op (ADDR_EXPR
, td3
, 0);
628 /* Determine how T and V are related. */
629 boff
= dcast_base_hint (static_type
, target_type
);
631 /* Since expr is used twice below, save it. */
632 expr
= save_expr (expr
);
635 if (tc
== REFERENCE_TYPE
)
636 expr1
= build_unary_op (ADDR_EXPR
, expr1
, 0);
639 (NULL_TREE
, expr1
, tree_cons
640 (NULL_TREE
, td3
, tree_cons
641 (NULL_TREE
, td2
, tree_cons
642 (NULL_TREE
, boff
, NULL_TREE
))));
644 dcast_fn
= dynamic_cast_node
;
652 push_nested_namespace (ns
);
653 tinfo_ptr
= xref_tag (class_type
,
654 get_identifier ("__class_type_info"),
655 /*tag_scope=*/ts_current
, false);
657 tinfo_ptr
= build_pointer_type
658 (build_qualified_type
659 (tinfo_ptr
, TYPE_QUAL_CONST
));
660 name
= "__dynamic_cast";
662 (NULL_TREE
, const_ptr_type_node
, tree_cons
663 (NULL_TREE
, tinfo_ptr
, tree_cons
664 (NULL_TREE
, tinfo_ptr
, tree_cons
665 (NULL_TREE
, ptrdiff_type_node
, void_list_node
))));
666 tmp
= build_function_type (ptr_type_node
, tmp
);
667 dcast_fn
= build_library_fn_ptr (name
, tmp
);
668 DECL_IS_PURE (dcast_fn
) = 1;
669 pop_nested_namespace (ns
);
670 dynamic_cast_node
= dcast_fn
;
672 result
= build_cxx_call (dcast_fn
, elems
);
674 if (tc
== REFERENCE_TYPE
)
676 tree bad
= throw_bad_cast ();
678 result
= save_expr (result
);
679 return build3 (COND_EXPR
, type
, result
, result
, bad
);
682 /* Now back to the type we want from a void*. */
683 result
= cp_convert (type
, result
);
684 return ifnonnull (expr
, result
);
688 errstr
= "source type is not polymorphic";
691 error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
692 expr
, exprtype
, type
, errstr
);
693 return error_mark_node
;
697 build_dynamic_cast (tree type
, tree expr
)
699 if (type
== error_mark_node
|| expr
== error_mark_node
)
700 return error_mark_node
;
702 /* Use of dynamic_cast when -fno-rtti is prohibited. */
705 error ("%<dynamic_cast%> not permitted with -fno-rtti");
706 return error_mark_node
;
709 if (processing_template_decl
)
711 expr
= build_min (DYNAMIC_CAST_EXPR
, type
, expr
);
712 TREE_SIDE_EFFECTS (expr
) = 1;
717 return convert_from_reference (build_dynamic_cast_1 (type
, expr
));
720 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
723 qualifier_flags (tree type
)
726 int quals
= cp_type_quals (type
);
728 if (quals
& TYPE_QUAL_CONST
)
730 if (quals
& TYPE_QUAL_VOLATILE
)
732 if (quals
& TYPE_QUAL_RESTRICT
)
737 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
738 contains a pointer to member of an incomplete class. */
741 target_incomplete_p (tree type
)
744 if (TYPE_PTRMEM_P (type
))
746 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)))
748 type
= TYPE_PTRMEM_POINTED_TO_TYPE (type
);
750 else if (TREE_CODE (type
) == POINTER_TYPE
)
751 type
= TREE_TYPE (type
);
753 return !COMPLETE_OR_VOID_TYPE_P (type
);
756 /* Returns true if TYPE involves an incomplete class type; in that
757 case, typeinfo variables for TYPE should be emitted with internal
761 involves_incomplete_p (tree type
)
763 switch (TREE_CODE (type
))
766 return target_incomplete_p (TREE_TYPE (type
));
771 (target_incomplete_p (TYPE_PTRMEM_POINTED_TO_TYPE (type
))
772 || !COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)));
775 if (TYPE_PTRMEMFUNC_P (type
))
779 if (!COMPLETE_TYPE_P (type
))
783 /* All other types do not involve incomplete class types. */
788 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
789 is the vtable pointer and NTBS name. The NTBS name is emitted as a
790 comdat const char array, so it becomes a unique key for the type. Generate
791 and emit that VAR_DECL here. (We can't always emit the type_info itself
792 as comdat, because of pointers to incomplete.) */
795 tinfo_base_init (tinfo_s
*ti
, tree target
)
797 tree init
= NULL_TREE
;
804 /* Generate the NTBS array variable. */
805 tree name_type
= build_cplus_array_type
806 (build_qualified_type (char_type_node
, TYPE_QUAL_CONST
),
808 tree name_string
= tinfo_name (target
);
810 /* Determine the name of the variable -- and remember with which
811 type it is associated. */
812 name_name
= mangle_typeinfo_string_for_type (target
);
813 TREE_TYPE (name_name
) = target
;
815 name_decl
= build_lang_decl (VAR_DECL
, name_name
, name_type
);
816 SET_DECL_ASSEMBLER_NAME (name_decl
, name_name
);
817 DECL_ARTIFICIAL (name_decl
) = 1;
818 DECL_IGNORED_P (name_decl
) = 1;
819 TREE_READONLY (name_decl
) = 1;
820 TREE_STATIC (name_decl
) = 1;
821 DECL_EXTERNAL (name_decl
) = 0;
822 DECL_TINFO_P (name_decl
) = 1;
823 if (involves_incomplete_p (target
))
825 TREE_PUBLIC (name_decl
) = 0;
826 DECL_INTERFACE_KNOWN (name_decl
) = 1;
829 set_linkage_according_to_type (target
, name_decl
);
830 import_export_decl (name_decl
);
831 DECL_INITIAL (name_decl
) = name_string
;
832 mark_used (name_decl
);
833 pushdecl_top_level_and_finish (name_decl
, name_string
);
836 vtable_ptr
= ti
->vtable
;
840 push_nested_namespace (abi_node
);
841 real_type
= xref_tag (class_type
, ti
->name
,
842 /*tag_scope=*/ts_current
, false);
843 pop_nested_namespace (abi_node
);
845 if (!COMPLETE_TYPE_P (real_type
))
847 /* We never saw a definition of this type, so we need to
848 tell the compiler that this is an exported class, as
849 indeed all of the __*_type_info classes are. */
850 SET_CLASSTYPE_INTERFACE_KNOWN (real_type
);
851 CLASSTYPE_INTERFACE_ONLY (real_type
) = 1;
854 vtable_ptr
= get_vtable_decl (real_type
, /*complete=*/1);
855 vtable_ptr
= build_unary_op (ADDR_EXPR
, vtable_ptr
, 0);
857 /* We need to point into the middle of the vtable. */
859 (PLUS_EXPR
, TREE_TYPE (vtable_ptr
), vtable_ptr
,
860 size_binop (MULT_EXPR
,
861 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
),
862 TYPE_SIZE_UNIT (vtable_entry_type
)));
864 ti
->vtable
= vtable_ptr
;
867 init
= tree_cons (NULL_TREE
, vtable_ptr
, init
);
869 init
= tree_cons (NULL_TREE
, decay_conversion (name_decl
), init
);
871 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
872 TREE_CONSTANT (init
) = 1;
873 TREE_INVARIANT (init
) = 1;
874 TREE_STATIC (init
) = 1;
875 init
= tree_cons (NULL_TREE
, init
, NULL_TREE
);
880 /* Return the CONSTRUCTOR expr for a type_info of TYPE. TI provides the
881 information about the particular type_info derivation, which adds no
882 additional fields to the type_info base. */
885 generic_initializer (tinfo_s
*ti
, tree target
)
887 tree init
= tinfo_base_init (ti
, target
);
889 init
= build_constructor_from_list (NULL_TREE
, init
);
890 TREE_CONSTANT (init
) = 1;
891 TREE_INVARIANT (init
) = 1;
892 TREE_STATIC (init
) = 1;
896 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
897 TI provides information about the particular type_info derivation,
898 which adds target type and qualifier flags members to the type_info base. */
901 ptr_initializer (tinfo_s
*ti
, tree target
)
903 tree init
= tinfo_base_init (ti
, target
);
904 tree to
= TREE_TYPE (target
);
905 int flags
= qualifier_flags (to
);
906 bool incomplete
= target_incomplete_p (to
);
910 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
911 init
= tree_cons (NULL_TREE
,
912 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
915 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
916 TREE_CONSTANT (init
) = 1;
917 TREE_INVARIANT (init
) = 1;
918 TREE_STATIC (init
) = 1;
922 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
923 TI provides information about the particular type_info derivation,
924 which adds class, target type and qualifier flags members to the type_info
928 ptm_initializer (tinfo_s
*ti
, tree target
)
930 tree init
= tinfo_base_init (ti
, target
);
931 tree to
= TYPE_PTRMEM_POINTED_TO_TYPE (target
);
932 tree klass
= TYPE_PTRMEM_CLASS_TYPE (target
);
933 int flags
= qualifier_flags (to
);
934 bool incomplete
= target_incomplete_p (to
);
938 if (!COMPLETE_TYPE_P (klass
))
940 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
941 init
= tree_cons (NULL_TREE
,
942 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
944 init
= tree_cons (NULL_TREE
,
945 get_tinfo_ptr (klass
),
948 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
949 TREE_CONSTANT (init
) = 1;
950 TREE_INVARIANT (init
) = 1;
951 TREE_STATIC (init
) = 1;
955 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
956 TI provides information about the particular __class_type_info derivation,
957 which adds hint flags and TRAIL initializers to the type_info base. */
960 class_initializer (tinfo_s
*ti
, tree target
, tree trail
)
962 tree init
= tinfo_base_init (ti
, target
);
964 TREE_CHAIN (init
) = trail
;
965 init
= build_constructor_from_list (NULL_TREE
, init
);
966 TREE_CONSTANT (init
) = 1;
967 TREE_INVARIANT (init
) = 1;
968 TREE_STATIC (init
) = 1;
972 /* Returns true if the typeinfo for type should be placed in
973 the runtime library. */
976 typeinfo_in_lib_p (tree type
)
978 /* The typeinfo objects for `T*' and `const T*' are in the runtime
979 library for simple types T. */
980 if (TREE_CODE (type
) == POINTER_TYPE
981 && (cp_type_quals (TREE_TYPE (type
)) == TYPE_QUAL_CONST
982 || cp_type_quals (TREE_TYPE (type
)) == TYPE_UNQUALIFIED
))
983 type
= TREE_TYPE (type
);
985 switch (TREE_CODE (type
))
999 /* Generate the initializer for the type info describing TYPE. TK_INDEX is
1000 the index of the descriptor in the tinfo_desc vector. */
1003 get_pseudo_ti_init (tree type
, unsigned tk_index
)
1005 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1007 gcc_assert (at_eof
);
1010 case TK_POINTER_MEMBER_TYPE
:
1011 return ptm_initializer (ti
, type
);
1013 case TK_POINTER_TYPE
:
1014 return ptr_initializer (ti
, type
);
1016 case TK_BUILTIN_TYPE
:
1017 case TK_ENUMERAL_TYPE
:
1018 case TK_FUNCTION_TYPE
:
1020 return generic_initializer (ti
, type
);
1023 return class_initializer (ti
, type
, NULL_TREE
);
1025 case TK_SI_CLASS_TYPE
:
1027 tree base_binfo
= BINFO_BASE_BINFO (TYPE_BINFO (type
), 0);
1028 tree tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1029 tree base_inits
= tree_cons (NULL_TREE
, tinfo
, NULL_TREE
);
1031 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1032 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1033 return class_initializer (ti
, type
, base_inits
);
1038 int hint
= ((CLASSTYPE_REPEATED_BASE_P (type
) << 0)
1039 | (CLASSTYPE_DIAMOND_SHAPED_P (type
) << 1));
1040 tree binfo
= TYPE_BINFO (type
);
1041 int nbases
= BINFO_N_BASE_BINFOS (binfo
);
1042 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1043 tree base_inits
= NULL_TREE
;
1046 gcc_assert (tk_index
>= TK_FIXED
);
1048 /* Generate the base information initializer. */
1049 for (ix
= nbases
; ix
--;)
1051 tree base_binfo
= BINFO_BASE_BINFO (binfo
, ix
);
1052 tree base_init
= NULL_TREE
;
1057 if (VEC_index (tree
, base_accesses
, ix
) == access_public_node
)
1059 tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1060 if (BINFO_VIRTUAL_P (base_binfo
))
1062 /* We store the vtable offset at which the virtual
1063 base offset can be found. */
1064 offset
= BINFO_VPTR_FIELD (base_binfo
);
1065 offset
= convert (sizetype
, offset
);
1069 offset
= BINFO_OFFSET (base_binfo
);
1071 /* Combine offset and flags into one field. */
1072 offset
= cp_build_binary_op (LSHIFT_EXPR
, offset
,
1073 build_int_cst (NULL_TREE
, 8));
1074 offset
= cp_build_binary_op (BIT_IOR_EXPR
, offset
,
1075 build_int_cst (NULL_TREE
, flags
));
1076 base_init
= tree_cons (NULL_TREE
, offset
, base_init
);
1077 base_init
= tree_cons (NULL_TREE
, tinfo
, base_init
);
1078 base_init
= build_constructor_from_list (NULL_TREE
, base_init
);
1079 base_inits
= tree_cons (NULL_TREE
, base_init
, base_inits
);
1081 base_inits
= build_constructor_from_list (NULL_TREE
, base_inits
);
1082 base_inits
= tree_cons (NULL_TREE
, base_inits
, NULL_TREE
);
1083 /* Prepend the number of bases. */
1084 base_inits
= tree_cons (NULL_TREE
,
1085 build_int_cst (NULL_TREE
, nbases
),
1087 /* Prepend the hint flags. */
1088 base_inits
= tree_cons (NULL_TREE
,
1089 build_int_cst (NULL_TREE
, hint
),
1092 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1093 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1094 return class_initializer (ti
, type
, base_inits
);
1099 /* Generate the RECORD_TYPE containing the data layout of a type_info
1100 derivative as used by the runtime. This layout must be consistent with
1101 that defined in the runtime support. Also generate the VAR_DECL for the
1102 type's vtable. We explicitly manage the vtable member, and name it for
1103 real type as used in the runtime. The RECORD type has a different name,
1104 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1105 is the generated type and TINFO_VTABLE_NAME is the name of the
1106 vtable. We have to delay generating the VAR_DECL of the vtable
1107 until the end of the translation, when we'll have seen the library
1108 definition, if there was one.
1110 REAL_NAME is the runtime's name of the type. Trailing arguments are
1111 additional FIELD_DECL's for the structure. The final argument must be
1115 create_pseudo_type_info (int tk
, const char *real_name
, ...)
1124 va_start (ap
, real_name
);
1126 /* Generate the pseudo type name. */
1127 pseudo_name
= alloca (strlen (real_name
) + 30);
1128 strcpy (pseudo_name
, real_name
);
1129 strcat (pseudo_name
, "_pseudo");
1131 sprintf (pseudo_name
+ strlen (pseudo_name
), "%d", tk
- TK_FIXED
);
1133 /* First field is the pseudo type_info base class. */
1134 fields
= build_decl (FIELD_DECL
, NULL_TREE
,
1135 VEC_index (tinfo_s
, tinfo_descs
,
1136 TK_TYPE_INFO_TYPE
)->type
);
1138 /* Now add the derived fields. */
1139 while ((field_decl
= va_arg (ap
, tree
)))
1141 TREE_CHAIN (field_decl
) = fields
;
1142 fields
= field_decl
;
1145 /* Create the pseudo type. */
1146 pseudo_type
= make_aggr_type (RECORD_TYPE
);
1147 finish_builtin_struct (pseudo_type
, pseudo_name
, fields
, NULL_TREE
);
1148 CLASSTYPE_AS_BASE (pseudo_type
) = pseudo_type
;
1150 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk
);
1151 ti
->type
= cp_build_qualified_type (pseudo_type
, TYPE_QUAL_CONST
);
1152 ti
->name
= get_identifier (real_name
);
1153 ti
->vtable
= NULL_TREE
;
1158 /* Return the index of a pseudo type info type node used to describe
1159 TYPE. TYPE must be a complete type (or cv void), except at the end
1160 of the translation unit. */
1163 get_pseudo_ti_index (tree type
)
1167 switch (TREE_CODE (type
))
1170 ix
= TK_POINTER_MEMBER_TYPE
;
1174 ix
= TK_POINTER_TYPE
;
1178 ix
= TK_ENUMERAL_TYPE
;
1182 ix
= TK_FUNCTION_TYPE
;
1191 if (TYPE_PTRMEMFUNC_P (type
))
1193 ix
= TK_POINTER_MEMBER_TYPE
;
1196 else if (!COMPLETE_TYPE_P (type
))
1199 cxx_incomplete_type_error (NULL_TREE
, type
);
1203 else if (!BINFO_N_BASE_BINFOS (TYPE_BINFO (type
)))
1210 tree binfo
= TYPE_BINFO (type
);
1211 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1212 tree base_binfo
= BINFO_BASE_BINFO (binfo
, 0);
1213 int num_bases
= BINFO_N_BASE_BINFOS (binfo
);
1216 && VEC_index (tree
, base_accesses
, 0) == access_public_node
1217 && !BINFO_VIRTUAL_P (base_binfo
)
1218 && integer_zerop (BINFO_OFFSET (base_binfo
)))
1220 /* single non-virtual public. */
1221 ix
= TK_SI_CLASS_TYPE
;
1227 tree array_domain
, base_array
;
1229 ix
= TK_FIXED
+ num_bases
;
1230 if (VEC_length (tinfo_s
, tinfo_descs
) <= ix
)
1232 /* too short, extend. */
1233 unsigned len
= VEC_length (tinfo_s
, tinfo_descs
);
1235 VEC_safe_grow (tinfo_s
, gc
, tinfo_descs
, ix
+ 1);
1236 while (VEC_iterate (tinfo_s
, tinfo_descs
, len
++, ti
))
1237 ti
->type
= ti
->vtable
= ti
->name
= NULL_TREE
;
1239 else if (VEC_index (tinfo_s
, tinfo_descs
, ix
)->type
)
1240 /* already created. */
1243 /* Create the array of __base_class_type_info entries.
1244 G++ 3.2 allocated an array that had one too many
1245 entries, and then filled that extra entries with
1247 if (abi_version_at_least (2))
1248 array_domain
= build_index_type (size_int (num_bases
- 1));
1250 array_domain
= build_index_type (size_int (num_bases
));
1252 build_array_type (VEC_index (tinfo_s
, tinfo_descs
,
1253 TK_BASE_TYPE
)->type
,
1256 push_nested_namespace (abi_node
);
1257 create_pseudo_type_info
1258 (ix
, "__vmi_class_type_info",
1259 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1260 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1261 build_decl (FIELD_DECL
, NULL_TREE
, base_array
),
1263 pop_nested_namespace (abi_node
);
1268 ix
= TK_BUILTIN_TYPE
;
1274 /* Make sure the required builtin types exist for generating the type_info
1275 variable definitions. */
1278 create_tinfo_types (void)
1282 gcc_assert (!tinfo_descs
);
1284 VEC_safe_grow (tinfo_s
, gc
, tinfo_descs
, TK_FIXED
);
1286 push_nested_namespace (abi_node
);
1288 /* Create the internal type_info structure. This is used as a base for
1289 the other structures. */
1293 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_ptr_type_node
);
1296 field
= build_decl (FIELD_DECL
, NULL_TREE
, const_string_type_node
);
1297 TREE_CHAIN (field
) = fields
;
1300 ti
= VEC_index (tinfo_s
, tinfo_descs
, TK_TYPE_INFO_TYPE
);
1301 ti
->type
= make_aggr_type (RECORD_TYPE
);
1302 ti
->vtable
= NULL_TREE
;
1303 ti
->name
= NULL_TREE
;
1304 finish_builtin_struct (ti
->type
, "__type_info_pseudo",
1306 TYPE_HAS_CONSTRUCTOR (ti
->type
) = 1;
1309 /* Fundamental type_info */
1310 create_pseudo_type_info (TK_BUILTIN_TYPE
, "__fundamental_type_info", NULL
);
1312 /* Array, function and enum type_info. No additional fields. */
1313 create_pseudo_type_info (TK_ARRAY_TYPE
, "__array_type_info", NULL
);
1314 create_pseudo_type_info (TK_FUNCTION_TYPE
, "__function_type_info", NULL
);
1315 create_pseudo_type_info (TK_ENUMERAL_TYPE
, "__enum_type_info", NULL
);
1317 /* Class type_info. No additional fields. */
1318 create_pseudo_type_info (TK_CLASS_TYPE
, "__class_type_info", NULL
);
1320 /* Single public non-virtual base class. Add pointer to base class.
1321 This is really a descendant of __class_type_info. */
1322 create_pseudo_type_info (TK_SI_CLASS_TYPE
, "__si_class_type_info",
1323 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1326 /* Base class internal helper. Pointer to base type, offset to base,
1331 field
= build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
);
1334 field
= build_decl (FIELD_DECL
, NULL_TREE
, integer_types
[itk_long
]);
1335 TREE_CHAIN (field
) = fields
;
1338 ti
= VEC_index (tinfo_s
, tinfo_descs
, TK_BASE_TYPE
);
1340 ti
->type
= make_aggr_type (RECORD_TYPE
);
1341 ti
->vtable
= NULL_TREE
;
1342 ti
->name
= NULL_TREE
;
1343 finish_builtin_struct (ti
->type
, "__base_class_type_info_pseudo",
1345 TYPE_HAS_CONSTRUCTOR (ti
->type
) = 1;
1348 /* Pointer type_info. Adds two fields, qualification mask
1349 and pointer to the pointed to type. This is really a descendant of
1350 __pbase_type_info. */
1351 create_pseudo_type_info (TK_POINTER_TYPE
, "__pointer_type_info",
1352 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1353 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1356 /* Pointer to member data type_info. Add qualifications flags,
1357 pointer to the member's type info and pointer to the class.
1358 This is really a descendant of __pbase_type_info. */
1359 create_pseudo_type_info (TK_POINTER_MEMBER_TYPE
,
1360 "__pointer_to_member_type_info",
1361 build_decl (FIELD_DECL
, NULL_TREE
, integer_type_node
),
1362 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1363 build_decl (FIELD_DECL
, NULL_TREE
, type_info_ptr_type
),
1366 pop_nested_namespace (abi_node
);
1369 /* Emit the type_info descriptors which are guaranteed to be in the runtime
1370 support. Generating them here guarantees consistency with the other
1371 structures. We use the following heuristic to determine when the runtime
1372 is being generated. If std::__fundamental_type_info is defined, and its
1373 destructor is defined, then the runtime is being built. */
1376 emit_support_tinfos (void)
1378 static tree
*const fundamentals
[] =
1383 &char_type_node
, &signed_char_type_node
, &unsigned_char_type_node
,
1384 &short_integer_type_node
, &short_unsigned_type_node
,
1385 &integer_type_node
, &unsigned_type_node
,
1386 &long_integer_type_node
, &long_unsigned_type_node
,
1387 &long_long_integer_type_node
, &long_long_unsigned_type_node
,
1388 &float_type_node
, &double_type_node
, &long_double_type_node
,
1392 tree bltn_type
, dtor
;
1394 push_nested_namespace (abi_node
);
1395 bltn_type
= xref_tag (class_type
,
1396 get_identifier ("__fundamental_type_info"),
1397 /*tag_scope=*/ts_current
, false);
1398 pop_nested_namespace (abi_node
);
1399 if (!COMPLETE_TYPE_P (bltn_type
))
1401 dtor
= CLASSTYPE_DESTRUCTORS (bltn_type
);
1402 if (!dtor
|| DECL_EXTERNAL (dtor
))
1405 for (ix
= 0; fundamentals
[ix
]; ix
++)
1407 tree bltn
= *fundamentals
[ix
];
1412 types
[1] = build_pointer_type (bltn
);
1413 types
[2] = build_pointer_type (build_qualified_type (bltn
,
1416 for (i
= 0; i
< 3; ++i
)
1420 tinfo
= get_tinfo_decl (types
[i
]);
1421 TREE_USED (tinfo
) = 1;
1422 mark_needed (tinfo
);
1423 /* The C++ ABI requires that these objects be COMDAT. But,
1424 On systems without weak symbols, initialized COMDAT
1425 objects are emitted with internal linkage. (See
1426 comdat_linkage for details.) Since we want these objects
1427 to have external linkage so that copies do not have to be
1428 emitted in code outside the runtime library, we make them
1432 gcc_assert (TREE_PUBLIC (tinfo
) && !DECL_COMDAT (tinfo
));
1433 DECL_INTERFACE_KNOWN (tinfo
) = 1;
1439 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1440 tinfo decl. Determine whether it needs emitting, and if so
1441 generate the initializer. */
1444 emit_tinfo_decl (tree decl
)
1446 tree type
= TREE_TYPE (DECL_NAME (decl
));
1447 int in_library
= typeinfo_in_lib_p (type
);
1449 gcc_assert (DECL_TINFO_P (decl
));
1454 DECL_EXTERNAL (decl
) = 0;
1457 /* If we're not in the runtime, then DECL (which is already
1458 DECL_EXTERNAL) will not be defined here. */
1459 DECL_INTERFACE_KNOWN (decl
) = 1;
1463 else if (involves_incomplete_p (type
))
1465 if (!decl_needed_p (decl
))
1467 /* If TYPE involves an incomplete class type, then the typeinfo
1468 object will be emitted with internal linkage. There is no
1469 way to know whether or not types are incomplete until the end
1470 of the compilation, so this determination must be deferred
1471 until this point. */
1472 TREE_PUBLIC (decl
) = 0;
1473 DECL_EXTERNAL (decl
) = 0;
1474 DECL_INTERFACE_KNOWN (decl
) = 1;
1477 import_export_decl (decl
);
1478 if (DECL_NOT_REALLY_EXTERN (decl
) && decl_needed_p (decl
))
1482 DECL_EXTERNAL (decl
) = 0;
1483 init
= get_pseudo_ti_init (type
, get_pseudo_ti_index (type
));
1484 DECL_INITIAL (decl
) = init
;
1486 cp_finish_decl (decl
, init
, NULL_TREE
, 0);
1493 #include "gt-cp-rtti.h"