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 /* Save casted types in the function's used types hash table. */
468 used_types_insert (type
);
470 /* T shall be a pointer or reference to a complete class type, or
471 `pointer to cv void''. */
475 if (TREE_CODE (TREE_TYPE (type
)) == VOID_TYPE
)
479 if (! IS_AGGR_TYPE (TREE_TYPE (type
)))
481 errstr
= "target is not pointer or reference to class";
484 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (type
))))
486 errstr
= "target is not pointer or reference to complete type";
492 errstr
= "target is not pointer or reference";
496 if (tc
== POINTER_TYPE
)
498 /* If T is a pointer type, v shall be an rvalue of a pointer to
499 complete class type, and the result is an rvalue of type T. */
501 if (TREE_CODE (exprtype
) != POINTER_TYPE
)
503 errstr
= "source is not a pointer";
506 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
508 errstr
= "source is not a pointer to class";
511 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
513 errstr
= "source is a pointer to incomplete type";
519 exprtype
= build_reference_type (exprtype
);
521 /* T is a reference type, v shall be an lvalue of a complete class
522 type, and the result is an lvalue of the type referred to by T. */
524 if (! IS_AGGR_TYPE (TREE_TYPE (exprtype
)))
526 errstr
= "source is not of class type";
529 if (!COMPLETE_TYPE_P (complete_type (TREE_TYPE (exprtype
))))
531 errstr
= "source is of incomplete class type";
535 /* Apply trivial conversion T -> T& for dereferenced ptrs. */
536 expr
= convert_to_reference (exprtype
, expr
, CONV_IMPLICIT
,
537 LOOKUP_NORMAL
, NULL_TREE
);
540 /* The dynamic_cast operator shall not cast away constness. */
541 if (!at_least_as_qualified_p (TREE_TYPE (type
),
542 TREE_TYPE (exprtype
)))
544 errstr
= "conversion casts away constness";
548 /* If *type is an unambiguous accessible base class of *exprtype,
549 convert statically. */
553 binfo
= lookup_base (TREE_TYPE (exprtype
), TREE_TYPE (type
),
558 expr
= build_base_path (PLUS_EXPR
, convert_from_reference (expr
),
560 if (TREE_CODE (exprtype
) == POINTER_TYPE
)
561 expr
= rvalue (expr
);
566 /* Otherwise *exprtype must be a polymorphic class (have a vtbl). */
567 if (TYPE_POLYMORPHIC_P (TREE_TYPE (exprtype
)))
570 /* if TYPE is `void *', return pointer to complete object. */
571 if (tc
== POINTER_TYPE
&& VOID_TYPE_P (TREE_TYPE (type
)))
573 /* if b is an object, dynamic_cast<void *>(&b) == (void *)&b. */
574 if (TREE_CODE (expr
) == ADDR_EXPR
575 && TREE_CODE (TREE_OPERAND (expr
, 0)) == VAR_DECL
576 && TREE_CODE (TREE_TYPE (TREE_OPERAND (expr
, 0))) == RECORD_TYPE
)
577 return build1 (NOP_EXPR
, type
, expr
);
579 /* Since expr is used twice below, save it. */
580 expr
= save_expr (expr
);
582 expr1
= build_headof (expr
);
583 if (TREE_TYPE (expr1
) != type
)
584 expr1
= build1 (NOP_EXPR
, type
, expr1
);
585 return ifnonnull (expr
, expr1
);
590 tree result
, td2
, td3
, elems
;
591 tree static_type
, target_type
, boff
;
593 /* If we got here, we can't convert statically. Therefore,
594 dynamic_cast<D&>(b) (b an object) cannot succeed. */
595 if (tc
== REFERENCE_TYPE
)
597 if (TREE_CODE (old_expr
) == VAR_DECL
598 && TREE_CODE (TREE_TYPE (old_expr
)) == RECORD_TYPE
)
600 tree expr
= throw_bad_cast ();
601 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
603 /* Bash it to the expected type. */
604 TREE_TYPE (expr
) = type
;
608 /* Ditto for dynamic_cast<D*>(&b). */
609 else if (TREE_CODE (expr
) == ADDR_EXPR
)
611 tree op
= TREE_OPERAND (expr
, 0);
612 if (TREE_CODE (op
) == VAR_DECL
613 && TREE_CODE (TREE_TYPE (op
)) == RECORD_TYPE
)
615 warning (0, "dynamic_cast of %q#D to %q#T can never succeed",
617 retval
= build_int_cst (type
, 0);
622 target_type
= TYPE_MAIN_VARIANT (TREE_TYPE (type
));
623 static_type
= TYPE_MAIN_VARIANT (TREE_TYPE (exprtype
));
624 td2
= get_tinfo_decl (target_type
);
626 td2
= build_unary_op (ADDR_EXPR
, td2
, 0);
627 td3
= get_tinfo_decl (static_type
);
629 td3
= build_unary_op (ADDR_EXPR
, td3
, 0);
631 /* Determine how T and V are related. */
632 boff
= dcast_base_hint (static_type
, target_type
);
634 /* Since expr is used twice below, save it. */
635 expr
= save_expr (expr
);
638 if (tc
== REFERENCE_TYPE
)
639 expr1
= build_unary_op (ADDR_EXPR
, expr1
, 0);
642 (NULL_TREE
, expr1
, tree_cons
643 (NULL_TREE
, td3
, tree_cons
644 (NULL_TREE
, td2
, tree_cons
645 (NULL_TREE
, boff
, NULL_TREE
))));
647 dcast_fn
= dynamic_cast_node
;
655 push_nested_namespace (ns
);
656 tinfo_ptr
= xref_tag (class_type
,
657 get_identifier ("__class_type_info"),
658 /*tag_scope=*/ts_current
, false);
660 tinfo_ptr
= build_pointer_type
661 (build_qualified_type
662 (tinfo_ptr
, TYPE_QUAL_CONST
));
663 name
= "__dynamic_cast";
665 (NULL_TREE
, const_ptr_type_node
, tree_cons
666 (NULL_TREE
, tinfo_ptr
, tree_cons
667 (NULL_TREE
, tinfo_ptr
, tree_cons
668 (NULL_TREE
, ptrdiff_type_node
, void_list_node
))));
669 tmp
= build_function_type (ptr_type_node
, tmp
);
670 dcast_fn
= build_library_fn_ptr (name
, tmp
);
671 DECL_IS_PURE (dcast_fn
) = 1;
672 pop_nested_namespace (ns
);
673 dynamic_cast_node
= dcast_fn
;
675 result
= build_cxx_call (dcast_fn
, elems
);
677 if (tc
== REFERENCE_TYPE
)
679 tree bad
= throw_bad_cast ();
681 result
= save_expr (result
);
682 return build3 (COND_EXPR
, type
, result
, result
, bad
);
685 /* Now back to the type we want from a void*. */
686 result
= cp_convert (type
, result
);
687 return ifnonnull (expr
, result
);
691 errstr
= "source type is not polymorphic";
694 error ("cannot dynamic_cast %qE (of type %q#T) to type %q#T (%s)",
695 expr
, exprtype
, type
, errstr
);
696 return error_mark_node
;
700 build_dynamic_cast (tree type
, tree expr
)
702 if (type
== error_mark_node
|| expr
== error_mark_node
)
703 return error_mark_node
;
705 /* Use of dynamic_cast when -fno-rtti is prohibited. */
708 error ("%<dynamic_cast%> not permitted with -fno-rtti");
709 return error_mark_node
;
712 if (processing_template_decl
)
714 expr
= build_min (DYNAMIC_CAST_EXPR
, type
, expr
);
715 TREE_SIDE_EFFECTS (expr
) = 1;
720 return convert_from_reference (build_dynamic_cast_1 (type
, expr
));
723 /* Return the runtime bit mask encoding the qualifiers of TYPE. */
726 qualifier_flags (tree type
)
729 int quals
= cp_type_quals (type
);
731 if (quals
& TYPE_QUAL_CONST
)
733 if (quals
& TYPE_QUAL_VOLATILE
)
735 if (quals
& TYPE_QUAL_RESTRICT
)
740 /* Return true, if the pointer chain TYPE ends at an incomplete type, or
741 contains a pointer to member of an incomplete class. */
744 target_incomplete_p (tree type
)
747 if (TYPE_PTRMEM_P (type
))
749 if (!COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)))
751 type
= TYPE_PTRMEM_POINTED_TO_TYPE (type
);
753 else if (TREE_CODE (type
) == POINTER_TYPE
)
754 type
= TREE_TYPE (type
);
756 return !COMPLETE_OR_VOID_TYPE_P (type
);
759 /* Returns true if TYPE involves an incomplete class type; in that
760 case, typeinfo variables for TYPE should be emitted with internal
764 involves_incomplete_p (tree type
)
766 switch (TREE_CODE (type
))
769 return target_incomplete_p (TREE_TYPE (type
));
774 (target_incomplete_p (TYPE_PTRMEM_POINTED_TO_TYPE (type
))
775 || !COMPLETE_TYPE_P (TYPE_PTRMEM_CLASS_TYPE (type
)));
778 if (TYPE_PTRMEMFUNC_P (type
))
782 if (!COMPLETE_TYPE_P (type
))
786 /* All other types do not involve incomplete class types. */
791 /* Return a CONSTRUCTOR for the common part of the type_info objects. This
792 is the vtable pointer and NTBS name. The NTBS name is emitted as a
793 comdat const char array, so it becomes a unique key for the type. Generate
794 and emit that VAR_DECL here. (We can't always emit the type_info itself
795 as comdat, because of pointers to incomplete.) */
798 tinfo_base_init (tinfo_s
*ti
, tree target
)
800 tree init
= NULL_TREE
;
807 /* Generate the NTBS array variable. */
808 tree name_type
= build_cplus_array_type
809 (build_qualified_type (char_type_node
, TYPE_QUAL_CONST
),
811 tree name_string
= tinfo_name (target
);
813 /* Determine the name of the variable -- and remember with which
814 type it is associated. */
815 name_name
= mangle_typeinfo_string_for_type (target
);
816 TREE_TYPE (name_name
) = target
;
818 name_decl
= build_lang_decl (VAR_DECL
, name_name
, name_type
);
819 SET_DECL_ASSEMBLER_NAME (name_decl
, name_name
);
820 DECL_ARTIFICIAL (name_decl
) = 1;
821 DECL_IGNORED_P (name_decl
) = 1;
822 TREE_READONLY (name_decl
) = 1;
823 TREE_STATIC (name_decl
) = 1;
824 DECL_EXTERNAL (name_decl
) = 0;
825 DECL_TINFO_P (name_decl
) = 1;
826 if (involves_incomplete_p (target
))
828 TREE_PUBLIC (name_decl
) = 0;
829 DECL_INTERFACE_KNOWN (name_decl
) = 1;
832 set_linkage_according_to_type (target
, name_decl
);
833 import_export_decl (name_decl
);
834 DECL_INITIAL (name_decl
) = name_string
;
835 mark_used (name_decl
);
836 pushdecl_top_level_and_finish (name_decl
, name_string
);
839 vtable_ptr
= ti
->vtable
;
843 push_nested_namespace (abi_node
);
844 real_type
= xref_tag (class_type
, ti
->name
,
845 /*tag_scope=*/ts_current
, false);
846 pop_nested_namespace (abi_node
);
848 if (!COMPLETE_TYPE_P (real_type
))
850 /* We never saw a definition of this type, so we need to
851 tell the compiler that this is an exported class, as
852 indeed all of the __*_type_info classes are. */
853 SET_CLASSTYPE_INTERFACE_KNOWN (real_type
);
854 CLASSTYPE_INTERFACE_ONLY (real_type
) = 1;
857 vtable_ptr
= get_vtable_decl (real_type
, /*complete=*/1);
858 vtable_ptr
= build_unary_op (ADDR_EXPR
, vtable_ptr
, 0);
860 /* We need to point into the middle of the vtable. */
862 (PLUS_EXPR
, TREE_TYPE (vtable_ptr
), vtable_ptr
,
863 size_binop (MULT_EXPR
,
864 size_int (2 * TARGET_VTABLE_DATA_ENTRY_DISTANCE
),
865 TYPE_SIZE_UNIT (vtable_entry_type
)));
867 ti
->vtable
= vtable_ptr
;
870 init
= tree_cons (NULL_TREE
, vtable_ptr
, init
);
872 init
= tree_cons (NULL_TREE
, decay_conversion (name_decl
), init
);
874 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
875 TREE_CONSTANT (init
) = 1;
876 TREE_INVARIANT (init
) = 1;
877 TREE_STATIC (init
) = 1;
878 init
= tree_cons (NULL_TREE
, init
, NULL_TREE
);
883 /* Return the CONSTRUCTOR expr for a type_info of TYPE. TI provides the
884 information about the particular type_info derivation, which adds no
885 additional fields to the type_info base. */
888 generic_initializer (tinfo_s
*ti
, tree target
)
890 tree init
= tinfo_base_init (ti
, target
);
892 init
= build_constructor_from_list (NULL_TREE
, init
);
893 TREE_CONSTANT (init
) = 1;
894 TREE_INVARIANT (init
) = 1;
895 TREE_STATIC (init
) = 1;
899 /* Return the CONSTRUCTOR expr for a type_info of pointer TYPE.
900 TI provides information about the particular type_info derivation,
901 which adds target type and qualifier flags members to the type_info base. */
904 ptr_initializer (tinfo_s
*ti
, tree target
)
906 tree init
= tinfo_base_init (ti
, target
);
907 tree to
= TREE_TYPE (target
);
908 int flags
= qualifier_flags (to
);
909 bool incomplete
= target_incomplete_p (to
);
913 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
914 init
= tree_cons (NULL_TREE
,
915 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
918 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
919 TREE_CONSTANT (init
) = 1;
920 TREE_INVARIANT (init
) = 1;
921 TREE_STATIC (init
) = 1;
925 /* Return the CONSTRUCTOR expr for a type_info of pointer to member data TYPE.
926 TI provides information about the particular type_info derivation,
927 which adds class, target type and qualifier flags members to the type_info
931 ptm_initializer (tinfo_s
*ti
, tree target
)
933 tree init
= tinfo_base_init (ti
, target
);
934 tree to
= TYPE_PTRMEM_POINTED_TO_TYPE (target
);
935 tree klass
= TYPE_PTRMEM_CLASS_TYPE (target
);
936 int flags
= qualifier_flags (to
);
937 bool incomplete
= target_incomplete_p (to
);
941 if (!COMPLETE_TYPE_P (klass
))
943 init
= tree_cons (NULL_TREE
, build_int_cst (NULL_TREE
, flags
), init
);
944 init
= tree_cons (NULL_TREE
,
945 get_tinfo_ptr (TYPE_MAIN_VARIANT (to
)),
947 init
= tree_cons (NULL_TREE
,
948 get_tinfo_ptr (klass
),
951 init
= build_constructor_from_list (NULL_TREE
, nreverse (init
));
952 TREE_CONSTANT (init
) = 1;
953 TREE_INVARIANT (init
) = 1;
954 TREE_STATIC (init
) = 1;
958 /* Return the CONSTRUCTOR expr for a type_info of class TYPE.
959 TI provides information about the particular __class_type_info derivation,
960 which adds hint flags and TRAIL initializers to the type_info base. */
963 class_initializer (tinfo_s
*ti
, tree target
, tree trail
)
965 tree init
= tinfo_base_init (ti
, target
);
967 TREE_CHAIN (init
) = trail
;
968 init
= build_constructor_from_list (NULL_TREE
, init
);
969 TREE_CONSTANT (init
) = 1;
970 TREE_INVARIANT (init
) = 1;
971 TREE_STATIC (init
) = 1;
975 /* Returns true if the typeinfo for type should be placed in
976 the runtime library. */
979 typeinfo_in_lib_p (tree type
)
981 /* The typeinfo objects for `T*' and `const T*' are in the runtime
982 library for simple types T. */
983 if (TREE_CODE (type
) == POINTER_TYPE
984 && (cp_type_quals (TREE_TYPE (type
)) == TYPE_QUAL_CONST
985 || cp_type_quals (TREE_TYPE (type
)) == TYPE_UNQUALIFIED
))
986 type
= TREE_TYPE (type
);
988 switch (TREE_CODE (type
))
1001 /* Generate the initializer for the type info describing TYPE. TK_INDEX is
1002 the index of the descriptor in the tinfo_desc vector. */
1005 get_pseudo_ti_init (tree type
, unsigned tk_index
)
1007 tinfo_s
*ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1009 gcc_assert (at_eof
);
1012 case TK_POINTER_MEMBER_TYPE
:
1013 return ptm_initializer (ti
, type
);
1015 case TK_POINTER_TYPE
:
1016 return ptr_initializer (ti
, type
);
1018 case TK_BUILTIN_TYPE
:
1019 case TK_ENUMERAL_TYPE
:
1020 case TK_FUNCTION_TYPE
:
1022 return generic_initializer (ti
, type
);
1025 return class_initializer (ti
, type
, NULL_TREE
);
1027 case TK_SI_CLASS_TYPE
:
1029 tree base_binfo
= BINFO_BASE_BINFO (TYPE_BINFO (type
), 0);
1030 tree tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1031 tree base_inits
= tree_cons (NULL_TREE
, tinfo
, NULL_TREE
);
1033 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1034 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1035 return class_initializer (ti
, type
, base_inits
);
1040 int hint
= ((CLASSTYPE_REPEATED_BASE_P (type
) << 0)
1041 | (CLASSTYPE_DIAMOND_SHAPED_P (type
) << 1));
1042 tree binfo
= TYPE_BINFO (type
);
1043 int nbases
= BINFO_N_BASE_BINFOS (binfo
);
1044 VEC(tree
,gc
) *base_accesses
= BINFO_BASE_ACCESSES (binfo
);
1045 tree base_inits
= NULL_TREE
;
1048 gcc_assert (tk_index
>= TK_FIXED
);
1050 /* Generate the base information initializer. */
1051 for (ix
= nbases
; ix
--;)
1053 tree base_binfo
= BINFO_BASE_BINFO (binfo
, ix
);
1054 tree base_init
= NULL_TREE
;
1059 if (VEC_index (tree
, base_accesses
, ix
) == access_public_node
)
1061 tinfo
= get_tinfo_ptr (BINFO_TYPE (base_binfo
));
1062 if (BINFO_VIRTUAL_P (base_binfo
))
1064 /* We store the vtable offset at which the virtual
1065 base offset can be found. */
1066 offset
= BINFO_VPTR_FIELD (base_binfo
);
1067 offset
= convert (sizetype
, offset
);
1071 offset
= BINFO_OFFSET (base_binfo
);
1073 /* Combine offset and flags into one field. */
1074 offset
= cp_build_binary_op (LSHIFT_EXPR
, offset
,
1075 build_int_cst (NULL_TREE
, 8));
1076 offset
= cp_build_binary_op (BIT_IOR_EXPR
, offset
,
1077 build_int_cst (NULL_TREE
, flags
));
1078 base_init
= tree_cons (NULL_TREE
, offset
, base_init
);
1079 base_init
= tree_cons (NULL_TREE
, tinfo
, base_init
);
1080 base_init
= build_constructor_from_list (NULL_TREE
, base_init
);
1081 base_inits
= tree_cons (NULL_TREE
, base_init
, base_inits
);
1083 base_inits
= build_constructor_from_list (NULL_TREE
, base_inits
);
1084 base_inits
= tree_cons (NULL_TREE
, base_inits
, NULL_TREE
);
1085 /* Prepend the number of bases. */
1086 base_inits
= tree_cons (NULL_TREE
,
1087 build_int_cst (NULL_TREE
, nbases
),
1089 /* Prepend the hint flags. */
1090 base_inits
= tree_cons (NULL_TREE
,
1091 build_int_cst (NULL_TREE
, hint
),
1094 /* get_tinfo_ptr might have reallocated the tinfo_descs vector. */
1095 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk_index
);
1096 return class_initializer (ti
, type
, base_inits
);
1101 /* Generate the RECORD_TYPE containing the data layout of a type_info
1102 derivative as used by the runtime. This layout must be consistent with
1103 that defined in the runtime support. Also generate the VAR_DECL for the
1104 type's vtable. We explicitly manage the vtable member, and name it for
1105 real type as used in the runtime. The RECORD type has a different name,
1106 to avoid collisions. Return a TREE_LIST who's TINFO_PSEUDO_TYPE
1107 is the generated type and TINFO_VTABLE_NAME is the name of the
1108 vtable. We have to delay generating the VAR_DECL of the vtable
1109 until the end of the translation, when we'll have seen the library
1110 definition, if there was one.
1112 REAL_NAME is the runtime's name of the type. Trailing arguments are
1113 additional FIELD_DECL's for the structure. The final argument must be
1117 create_pseudo_type_info (int tk
, const char *real_name
, ...)
1126 va_start (ap
, real_name
);
1128 /* Generate the pseudo type name. */
1129 pseudo_name
= (char *) alloca (strlen (real_name
) + 30);
1130 strcpy (pseudo_name
, real_name
);
1131 strcat (pseudo_name
, "_pseudo");
1133 sprintf (pseudo_name
+ strlen (pseudo_name
), "%d", tk
- TK_FIXED
);
1135 /* First field is the pseudo type_info base class. */
1136 fields
= build_decl (FIELD_DECL
, NULL_TREE
,
1137 VEC_index (tinfo_s
, tinfo_descs
,
1138 TK_TYPE_INFO_TYPE
)->type
);
1140 /* Now add the derived fields. */
1141 while ((field_decl
= va_arg (ap
, tree
)))
1143 TREE_CHAIN (field_decl
) = fields
;
1144 fields
= field_decl
;
1147 /* Create the pseudo type. */
1148 pseudo_type
= make_aggr_type (RECORD_TYPE
);
1149 finish_builtin_struct (pseudo_type
, pseudo_name
, fields
, NULL_TREE
);
1150 CLASSTYPE_AS_BASE (pseudo_type
) = pseudo_type
;
1152 ti
= VEC_index (tinfo_s
, tinfo_descs
, tk
);
1153 ti
->type
= cp_build_qualified_type (pseudo_type
, TYPE_QUAL_CONST
);
1154 ti
->name
= get_identifier (real_name
);
1155 ti
->vtable
= NULL_TREE
;
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
1434 gcc_assert (TREE_PUBLIC (tinfo
) && !DECL_COMDAT (tinfo
));
1435 DECL_INTERFACE_KNOWN (tinfo
) = 1;
1441 /* Finish a type info decl. DECL_PTR is a pointer to an unemitted
1442 tinfo decl. Determine whether it needs emitting, and if so
1443 generate the initializer. */
1446 emit_tinfo_decl (tree decl
)
1448 tree type
= TREE_TYPE (DECL_NAME (decl
));
1449 int in_library
= typeinfo_in_lib_p (type
);
1451 gcc_assert (DECL_TINFO_P (decl
));
1456 DECL_EXTERNAL (decl
) = 0;
1459 /* If we're not in the runtime, then DECL (which is already
1460 DECL_EXTERNAL) will not be defined here. */
1461 DECL_INTERFACE_KNOWN (decl
) = 1;
1465 else if (involves_incomplete_p (type
))
1467 if (!decl_needed_p (decl
))
1469 /* If TYPE involves an incomplete class type, then the typeinfo
1470 object will be emitted with internal linkage. There is no
1471 way to know whether or not types are incomplete until the end
1472 of the compilation, so this determination must be deferred
1473 until this point. */
1474 TREE_PUBLIC (decl
) = 0;
1475 DECL_EXTERNAL (decl
) = 0;
1476 DECL_INTERFACE_KNOWN (decl
) = 1;
1479 import_export_decl (decl
);
1480 if (DECL_NOT_REALLY_EXTERN (decl
) && decl_needed_p (decl
))
1484 DECL_EXTERNAL (decl
) = 0;
1485 init
= get_pseudo_ti_init (type
, get_pseudo_ti_index (type
));
1486 DECL_INITIAL (decl
) = init
;
1488 finish_decl (decl
, init
, NULL_TREE
);
1495 #include "gt-cp-rtti.h"