1// ABI Support -*- C++ -*-
2
3// Copyright (C) 2000-2017 Free Software Foundation, Inc.
4//
5// This file is part of GCC.
6//
7// GCC is free software; you can redistribute it and/or modify
8// it under the terms of the GNU General Public License as published by
9// the Free Software Foundation; either version 3, or (at your option)
10// any later version.
11//
12// GCC is distributed in the hope that it will be useful,
13// but WITHOUT ANY WARRANTY; without even the implied warranty of
14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15// GNU General Public License for more details.
16//
17// Under Section 7 of GPL version 3, you are granted additional
18// permissions described in the GCC Runtime Library Exception, version
19// 3.1, as published by the Free Software Foundation.
20
21// You should have received a copy of the GNU General Public License and
22// a copy of the GCC Runtime Library Exception along with this program;
23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24// <http://www.gnu.org/licenses/>.
25
26// Written by Nathan Sidwell, Codesourcery LLC, <nathan@codesourcery.com>
27
28/* This file declares the new abi entry points into the runtime. It is not
29 normally necessary for user programs to include this header, or use the
30 entry points directly. However, this header is available should that be
31 needed.
32
33 Some of the entry points are intended for both C and C++, thus this header
34 is includable from both C and C++. Though the C++ specific parts are not
35 available in C, naturally enough. */
36
37/** @file cxxabi.h
38 * The header provides an interface to the C++ ABI.
39 */
40
41#ifndef _CXXABI_H
42#define _CXXABI_H 1
43
44#pragma GCC system_header
45
46#pragma GCC visibility push(default)
47
48#include <stddef.h>
49#include <bits/c++config.h>
50#include <bits/cxxabi_tweaks.h>
51#include <bits/cxxabi_forced.h>
52#include <bits/cxxabi_init_exception.h>
53
54#ifdef __cplusplus
55namespace __cxxabiv1
56{
57 extern "C"
58 {
59#endif
60
61 typedef __cxa_cdtor_return_type (*__cxa_cdtor_type)(void *);
62
63 // Allocate array.
64 void*
65 __cxa_vec_new(size_t __element_count, size_t __element_size,
66 size_t __padding_size, __cxa_cdtor_type __constructor,
67 __cxa_cdtor_type __destructor);
68
69 void*
70 __cxa_vec_new2(size_t __element_count, size_t __element_size,
71 size_t __padding_size, __cxa_cdtor_type __constructor,
72 __cxa_cdtor_type __destructor, void *(*__alloc) (size_t),
73 void (*__dealloc) (void*));
74
75 void*
76 __cxa_vec_new3(size_t __element_count, size_t __element_size,
77 size_t __padding_size, __cxa_cdtor_type __constructor,
78 __cxa_cdtor_type __destructor, void *(*__alloc) (size_t),
79 void (*__dealloc) (void*, size_t));
80
81 // Construct array.
82 __cxa_vec_ctor_return_type
83 __cxa_vec_ctor(void* __array_address, size_t __element_count,
84 size_t __element_size, __cxa_cdtor_type __constructor,
85 __cxa_cdtor_type __destructor);
86
87 __cxa_vec_ctor_return_type
88 __cxa_vec_cctor(void* __dest_array, void* __src_array,
89 size_t __element_count, size_t __element_size,
90 __cxa_cdtor_return_type (*__constructor) (void*, void*),
91 __cxa_cdtor_type __destructor);
92
93 // Destruct array.
94 void
95 __cxa_vec_dtor(void* __array_address, size_t __element_count,
96 size_t __element_size, __cxa_cdtor_type __destructor);
97
98 void
99 __cxa_vec_cleanup(void* __array_address, size_t __element_count, size_t __s,
100 __cxa_cdtor_type __destructor) _GLIBCXX_NOTHROW;
101
102 // Destruct and release array.
103 void
104 __cxa_vec_delete(void* __array_address, size_t __element_size,
105 size_t __padding_size, __cxa_cdtor_type __destructor);
106
107 void
108 __cxa_vec_delete2(void* __array_address, size_t __element_size,
109 size_t __padding_size, __cxa_cdtor_type __destructor,
110 void (*__dealloc) (void*));
111
112 void
113 __cxa_vec_delete3(void* __array_address, size_t __element_size,
114 size_t __padding_size, __cxa_cdtor_type __destructor,
115 void (*__dealloc) (void*, size_t));
116
117 int
118 __cxa_guard_acquire(__guard*);
119
120 void
121 __cxa_guard_release(__guard*) _GLIBCXX_NOTHROW;
122
123 void
124 __cxa_guard_abort(__guard*) _GLIBCXX_NOTHROW;
125
126 // DSO destruction.
127 int
128 __cxa_atexit(void (*)(void*), void*, void*) _GLIBCXX_NOTHROW;
129
130 int
131 __cxa_finalize(void*);
132
133 // TLS destruction.
134 int
135 __cxa_thread_atexit(void (*)(void*), void*, void *) _GLIBCXX_NOTHROW;
136
137 // Pure virtual functions.
138 void
139 __cxa_pure_virtual(void) __attribute__ ((__noreturn__));
140
141 void
142 __cxa_deleted_virtual(void) __attribute__ ((__noreturn__));
143
144 // Exception handling auxiliary.
145 void
146 __cxa_bad_cast() __attribute__((__noreturn__));
147
148 void
149 __cxa_bad_typeid() __attribute__((__noreturn__));
150
151 void
152 __cxa_throw_bad_array_new_length() __attribute__((__noreturn__));
153
154 /**
155 * @brief Demangling routine.
156 * ABI-mandated entry point in the C++ runtime library for demangling.
157 *
158 * @param __mangled_name A NUL-terminated character string
159 * containing the name to be demangled.
160 *
161 * @param __output_buffer A region of memory, allocated with
162 * malloc, of @a *__length bytes, into which the demangled name is
163 * stored. If @a __output_buffer is not long enough, it is
164 * expanded using realloc. @a __output_buffer may instead be NULL;
165 * in that case, the demangled name is placed in a region of memory
166 * allocated with malloc.
167 *
168 * @param __length If @a __length is non-NULL, the length of the
169 * buffer containing the demangled name is placed in @a *__length.
170 *
171 * @param __status @a *__status is set to one of the following values:
172 * 0: The demangling operation succeeded.
173 * -1: A memory allocation failure occurred.
174 * -2: @a mangled_name is not a valid name under the C++ ABI mangling rules.
175 * -3: One of the arguments is invalid.
176 *
177 * @return A pointer to the start of the NUL-terminated demangled
178 * name, or NULL if the demangling fails. The caller is
179 * responsible for deallocating this memory using @c free.
180 *
181 * The demangling is performed using the C++ ABI mangling rules,
182 * with GNU extensions. For example, this function is used in
183 * __gnu_cxx::__verbose_terminate_handler.
184 *
185 * See https://gcc.gnu.org/onlinedocs/libstdc++/manual/ext_demangling.html
186 * for other examples of use.
187 *
188 * @note The same demangling functionality is available via
189 * libiberty (@c <libiberty/demangle.h> and @c libiberty.a) in GCC
190 * 3.1 and later, but that requires explicit installation (@c
191 * --enable-install-libiberty) and uses a different API, although
192 * the ABI is unchanged.
193 */
194 char*
195 __cxa_demangle(const char* __mangled_name, char* __output_buffer,
196 size_t* __length, int* __status);
197
198#ifdef __cplusplus
199 }
200} // namespace __cxxabiv1
201#endif
202
203#ifdef __cplusplus
204
205#include <typeinfo>
206
207namespace __cxxabiv1
208{
209 // Type information for int, float etc.
210 class __fundamental_type_info : public std::type_info
211 {
212 public:
213 explicit
214 __fundamental_type_info(const char* __n) : std::type_info(__n) { }
215
216 virtual
217 ~__fundamental_type_info();
218 };
219
220 // Type information for array objects.
221 class __array_type_info : public std::type_info
222 {
223 public:
224 explicit
225 __array_type_info(const char* __n) : std::type_info(__n) { }
226
227 virtual
228 ~__array_type_info();
229 };
230
231 // Type information for functions (both member and non-member).
232 class __function_type_info : public std::type_info
233 {
234 public:
235 explicit
236 __function_type_info(const char* __n) : std::type_info(__n) { }
237
238 virtual
239 ~__function_type_info();
240
241 protected:
242 // Implementation defined member function.
243 virtual bool
244 __is_function_p() const;
245 };
246
247 // Type information for enumerations.
248 class __enum_type_info : public std::type_info
249 {
250 public:
251 explicit
252 __enum_type_info(const char* __n) : std::type_info(__n) { }
253
254 virtual
255 ~__enum_type_info();
256 };
257
258 // Common type information for simple pointers and pointers to member.
259 class __pbase_type_info : public std::type_info
260 {
261 public:
262 unsigned int __flags; // Qualification of the target object.
263 const std::type_info* __pointee; // Type of pointed to object.
264
265 explicit
266 __pbase_type_info(const char* __n, int __quals,
267 const std::type_info* __type)
268 : std::type_info(__n), __flags(__quals), __pointee(__type)
269 { }
270
271 virtual
272 ~__pbase_type_info();
273
274 // Implementation defined type.
275 enum __masks
276 {
277 __const_mask = 0x1,
278 __volatile_mask = 0x2,
279 __restrict_mask = 0x4,
280 __incomplete_mask = 0x8,
281 __incomplete_class_mask = 0x10,
282 __transaction_safe_mask = 0x20,
283 __noexcept_mask = 0x40
284 };
285
286 protected:
287 __pbase_type_info(const __pbase_type_info&);
288
289 __pbase_type_info&
290 operator=(const __pbase_type_info&);
291
292 // Implementation defined member functions.
293 virtual bool
294 __do_catch(const std::type_info* __thr_type, void** __thr_obj,
295 unsigned int __outer) const;
296
297 inline virtual bool
298 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
299 unsigned __outer) const;
300 };
301
302 inline bool __pbase_type_info::
303 __pointer_catch (const __pbase_type_info *thrown_type,
304 void **thr_obj,
305 unsigned outer) const
306 {
307 return __pointee->__do_catch (thrown_type->__pointee, thr_obj, outer + 2);
308 }
309
310 // Type information for simple pointers.
311 class __pointer_type_info : public __pbase_type_info
312 {
313 public:
314 explicit
315 __pointer_type_info(const char* __n, int __quals,
316 const std::type_info* __type)
317 : __pbase_type_info (__n, __quals, __type) { }
318
319
320 virtual
321 ~__pointer_type_info();
322
323 protected:
324 // Implementation defined member functions.
325 virtual bool
326 __is_pointer_p() const;
327
328 virtual bool
329 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
330 unsigned __outer) const;
331 };
332
333 class __class_type_info;
334
335 // Type information for a pointer to member variable.
336 class __pointer_to_member_type_info : public __pbase_type_info
337 {
338 public:
339 __class_type_info* __context; // Class of the member.
340
341 explicit
342 __pointer_to_member_type_info(const char* __n, int __quals,
343 const std::type_info* __type,
344 __class_type_info* __klass)
345 : __pbase_type_info(__n, __quals, __type), __context(__klass) { }
346
347 virtual
348 ~__pointer_to_member_type_info();
349
350 protected:
351 __pointer_to_member_type_info(const __pointer_to_member_type_info&);
352
353 __pointer_to_member_type_info&
354 operator=(const __pointer_to_member_type_info&);
355
356 // Implementation defined member function.
357 virtual bool
358 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
359 unsigned __outer) const;
360 };
361
362 // Helper class for __vmi_class_type.
363 class __base_class_type_info
364 {
365 public:
366 const __class_type_info* __base_type; // Base class type.
367#ifdef _GLIBCXX_LLP64
368 long long __offset_flags; // Offset and info.
369#else
370 long __offset_flags; // Offset and info.
371#endif
372
373 enum __offset_flags_masks
374 {
375 __virtual_mask = 0x1,
376 __public_mask = 0x2,
377 __hwm_bit = 2,
378 __offset_shift = 8 // Bits to shift offset.
379 };
380
381 // Implementation defined member functions.
382 bool
383 __is_virtual_p() const
384 { return __offset_flags & __virtual_mask; }
385
386 bool
387 __is_public_p() const
388 { return __offset_flags & __public_mask; }
389
390 ptrdiff_t
391 __offset() const
392 {
393 // This shift, being of a signed type, is implementation
394 // defined. GCC implements such shifts as arithmetic, which is
395 // what we want.
396 return static_cast<ptrdiff_t>(__offset_flags) >> __offset_shift;
397 }
398 };
399
400 // Type information for a class.
401 class __class_type_info : public std::type_info
402 {
403 public:
404 explicit
405 __class_type_info (const char *__n) : type_info(__n) { }
406
407 virtual
408 ~__class_type_info ();
409
410 // Implementation defined types.
411 // The type sub_kind tells us about how a base object is contained
412 // within a derived object. We often do this lazily, hence the
413 // UNKNOWN value. At other times we may use NOT_CONTAINED to mean
414 // not publicly contained.
415 enum __sub_kind
416 {
417 // We have no idea.
418 __unknown = 0,
419
420 // Not contained within us (in some circumstances this might
421 // mean not contained publicly)
422 __not_contained,
423
424 // Contained ambiguously.
425 __contained_ambig,
426
427 // Via a virtual path.
428 __contained_virtual_mask = __base_class_type_info::__virtual_mask,
429
430 // Via a public path.
431 __contained_public_mask = __base_class_type_info::__public_mask,
432
433 // Contained within us.
434 __contained_mask = 1 << __base_class_type_info::__hwm_bit,
435
436 __contained_private = __contained_mask,
437 __contained_public = __contained_mask | __contained_public_mask
438 };
439
440 struct __upcast_result;
441 struct __dyncast_result;
442
443 protected:
444 // Implementation defined member functions.
445 virtual bool
446 __do_upcast(const __class_type_info* __dst_type, void**__obj_ptr) const;
447
448 virtual bool
449 __do_catch(const type_info* __thr_type, void** __thr_obj,
450 unsigned __outer) const;
451
452 public:
453 // Helper for upcast. See if DST is us, or one of our bases.
454 // Return false if not found, true if found.
455 virtual bool
456 __do_upcast(const __class_type_info* __dst, const void* __obj,
457 __upcast_result& __restrict __result) const;
458
459 // Indicate whether SRC_PTR of type SRC_TYPE is contained publicly
460 // within OBJ_PTR. OBJ_PTR points to a base object of our type,
461 // which is the destination type. SRC2DST indicates how SRC
462 // objects might be contained within this type. If SRC_PTR is one
463 // of our SRC_TYPE bases, indicate the virtuality. Returns
464 // not_contained for non containment or private containment.
465 inline __sub_kind
466 __find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
467 const __class_type_info* __src_type,
468 const void* __src_ptr) const;
469
470 // Helper for dynamic cast. ACCESS_PATH gives the access from the
471 // most derived object to this base. DST_TYPE indicates the
472 // desired type we want. OBJ_PTR points to a base of our type
473 // within the complete object. SRC_TYPE indicates the static type
474 // started from and SRC_PTR points to that base within the most
475 // derived object. Fill in RESULT with what we find. Return true
476 // if we have located an ambiguous match.
477 virtual bool
478 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
479 const __class_type_info* __dst_type, const void* __obj_ptr,
480 const __class_type_info* __src_type, const void* __src_ptr,
481 __dyncast_result& __result) const;
482
483 // Helper for find_public_subobj. SRC2DST indicates how SRC_TYPE
484 // bases are inherited by the type started from -- which is not
485 // necessarily the current type. The current type will be a base
486 // of the destination type. OBJ_PTR points to the current base.
487 virtual __sub_kind
488 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
489 const __class_type_info* __src_type,
490 const void* __src_ptr) const;
491 };
492
493 // Type information for a class with a single non-virtual base.
494 class __si_class_type_info : public __class_type_info
495 {
496 public:
497 const __class_type_info* __base_type;
498
499 explicit
500 __si_class_type_info(const char *__n, const __class_type_info *__base)
501 : __class_type_info(__n), __base_type(__base) { }
502
503 virtual
504 ~__si_class_type_info();
505
506 protected:
507 __si_class_type_info(const __si_class_type_info&);
508
509 __si_class_type_info&
510 operator=(const __si_class_type_info&);
511
512 // Implementation defined member functions.
513 virtual bool
514 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
515 const __class_type_info* __dst_type, const void* __obj_ptr,
516 const __class_type_info* __src_type, const void* __src_ptr,
517 __dyncast_result& __result) const;
518
519 virtual __sub_kind
520 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
521 const __class_type_info* __src_type,
522 const void* __sub_ptr) const;
523
524 virtual bool
525 __do_upcast(const __class_type_info*__dst, const void*__obj,
526 __upcast_result& __restrict __result) const;
527 };
528
529 // Type information for a class with multiple and/or virtual bases.
530 class __vmi_class_type_info : public __class_type_info
531 {
532 public:
533 unsigned int __flags; // Details about the class hierarchy.
534 unsigned int __base_count; // Number of direct bases.
535
536 // The array of bases uses the trailing array struct hack so this
537 // class is not constructable with a normal constructor. It is
538 // internally generated by the compiler.
539 __base_class_type_info __base_info[1]; // Array of bases.
540
541 explicit
542 __vmi_class_type_info(const char* __n, int ___flags)
543 : __class_type_info(__n), __flags(___flags), __base_count(0) { }
544
545 virtual
546 ~__vmi_class_type_info();
547
548 // Implementation defined types.
549 enum __flags_masks
550 {
551 __non_diamond_repeat_mask = 0x1, // Distinct instance of repeated base.
552 __diamond_shaped_mask = 0x2, // Diamond shaped multiple inheritance.
553 __flags_unknown_mask = 0x10
554 };
555
556 protected:
557 // Implementation defined member functions.
558 virtual bool
559 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
560 const __class_type_info* __dst_type, const void* __obj_ptr,
561 const __class_type_info* __src_type, const void* __src_ptr,
562 __dyncast_result& __result) const;
563
564 virtual __sub_kind
565 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
566 const __class_type_info* __src_type,
567 const void* __src_ptr) const;
568
569 virtual bool
570 __do_upcast(const __class_type_info* __dst, const void* __obj,
571 __upcast_result& __restrict __result) const;
572 };
573
574 // Exception handling forward declarations.
575 struct __cxa_exception;
576 struct __cxa_refcounted_exception;
577 struct __cxa_dependent_exception;
578 struct __cxa_eh_globals;
579
580 extern "C"
581 {
582 // Dynamic cast runtime.
583
584 // src2dst has the following possible values
585 // >-1: src_type is a unique public non-virtual base of dst_type
586 // dst_ptr + src2dst == src_ptr
587 // -1: unspecified relationship
588 // -2: src_type is not a public base of dst_type
589 // -3: src_type is a multiple public non-virtual base of dst_type
590 void*
591 __dynamic_cast(const void* __src_ptr, // Starting object.
592 const __class_type_info* __src_type, // Static type of object.
593 const __class_type_info* __dst_type, // Desired target type.
594 ptrdiff_t __src2dst); // How src and dst are related.
595
596
597 // Exception handling runtime.
598
599 // The __cxa_eh_globals for the current thread can be obtained by using
600 // either of the following functions. The "fast" version assumes at least
601 // one prior call of __cxa_get_globals has been made from the current
602 // thread, so no initialization is necessary.
603 __cxa_eh_globals*
604 __cxa_get_globals() _GLIBCXX_NOTHROW __attribute__ ((__const__));
605
606 __cxa_eh_globals*
607 __cxa_get_globals_fast() _GLIBCXX_NOTHROW __attribute__ ((__const__));
608
609 // Free the space allocated for the primary exception.
610 void
611 __cxa_free_exception(void*) _GLIBCXX_NOTHROW;
612
613 // Throw the exception.
614 void
615 __cxa_throw(void*, std::type_info*, void (_GLIBCXX_CDTOR_CALLABI *) (void *))
616 __attribute__((__noreturn__));
617
618 // Used to implement exception handlers.
619 void*
620 __cxa_get_exception_ptr(void*) _GLIBCXX_NOTHROW __attribute__ ((__pure__));
621
622 void*
623 __cxa_begin_catch(void*) _GLIBCXX_NOTHROW;
624
625 void
626 __cxa_end_catch();
627
628 void
629 __cxa_rethrow() __attribute__((__noreturn__));
630
631 // Returns the type_info for the currently handled exception [15.3/8], or
632 // null if there is none.
633 std::type_info*
634 __cxa_current_exception_type() _GLIBCXX_NOTHROW __attribute__ ((__pure__));
635
636 // GNU Extensions.
637
638 // Allocate memory for a dependent exception.
639 __cxa_dependent_exception*
640 __cxa_allocate_dependent_exception() _GLIBCXX_NOTHROW;
641
642 // Free the space allocated for the dependent exception.
643 void
644 __cxa_free_dependent_exception(__cxa_dependent_exception*) _GLIBCXX_NOTHROW;
645
646 } // extern "C"
647
648 // A magic placeholder class that can be caught by reference
649 // to recognize foreign exceptions.
650 class __foreign_exception
651 {
652 virtual ~__foreign_exception() throw();
653 virtual void __pure_dummy() = 0; // prevent catch by value
654 };
655
656} // namespace __cxxabiv1
657
658/** @namespace abi
659 * @brief The cross-vendor C++ Application Binary Interface. A
660 * namespace alias to __cxxabiv1, but user programs should use the
661 * alias 'abi'.
662 *
663 * A brief overview of an ABI is given in the libstdc++ FAQ, question
664 * 5.8 (you may have a copy of the FAQ locally, or you can view the online
665 * version at http://gcc.gnu.org/onlinedocs/libstdc++/faq.html#5_8 ).
666 *
667 * GCC subscribes to a cross-vendor ABI for C++, sometimes
668 * called the IA64 ABI because it happens to be the native ABI for that
669 * platform. It is summarized at http://www.codesourcery.com/cxx-abi/
670 * along with the current specification.
671 *
672 * For users of GCC greater than or equal to 3.x, entry points are
673 * available in <cxxabi.h>, which notes, <em>'It is not normally
674 * necessary for user programs to include this header, or use the
675 * entry points directly. However, this header is available should
676 * that be needed.'</em>
677*/
678namespace abi = __cxxabiv1;
679
680namespace __gnu_cxx
681{
682 /**
683 * @brief Exception thrown by __cxa_guard_acquire.
684 * @ingroup exceptions
685 *
686 * 6.7[stmt.dcl]/4: If control re-enters the declaration (recursively)
687 * while the object is being initialized, the behavior is undefined.
688 *
689 * Since we already have a library function to handle locking, we might
690 * as well check for this situation and throw an exception.
691 * We use the second byte of the guard variable to remember that we're
692 * in the middle of an initialization.
693 */
694 class recursive_init_error: public std::exception
695 {
696 public:
697 recursive_init_error() throw() { }
698 virtual ~recursive_init_error() throw ();
699 };
700}
701#endif // __cplusplus
702
703#pragma GCC visibility pop
704
705#endif // __CXXABI_H
706