xref: /netbsd-src/external/gpl3/gcc/dist/libstdc++-v3/libsupc++/cxxabi.h (revision 6a493d6bc668897c91594964a732d38505b70cbb)
1 // new abi support -*- C++ -*-
2 
3 // Copyright (C) 2000, 2002, 2003, 2004, 2006, 2007, 2009, 2010
4 // Free Software Foundation, Inc.
5 //
6 // This file is part of GCC.
7 //
8 // GCC is free software; you can redistribute it and/or modify
9 // it under the terms of the GNU General Public License as published by
10 // the Free Software Foundation; either version 3, or (at your option)
11 // any later version.
12 //
13 // GCC is distributed in the hope that it will be useful,
14 // but WITHOUT ANY WARRANTY; without even the implied warranty of
15 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 // GNU General Public License for more details.
17 //
18 // Under Section 7 of GPL version 3, you are granted additional
19 // permissions described in the GCC Runtime Library Exception, version
20 // 3.1, as published by the Free Software Foundation.
21 
22 // You should have received a copy of the GNU General Public License and
23 // a copy of the GCC Runtime Library Exception along with this program;
24 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
25 // <http://www.gnu.org/licenses/>.
26 
27 // Written by Nathan Sidwell, Codesourcery LLC, <nathan@codesourcery.com>
28 
29 /* This file declares the new abi entry points into the runtime. It is not
30    normally necessary for user programs to include this header, or use the
31    entry points directly. However, this header is available should that be
32    needed.
33 
34    Some of the entry points are intended for both C and C++, thus this header
35    is includable from both C and C++. Though the C++ specific parts are not
36    available in C, naturally enough.  */
37 
38 /** @file cxxabi.h
39  *  The header provides an interface to the C++ ABI.
40  */
41 
42 #ifndef _CXXABI_H
43 #define _CXXABI_H 1
44 
45 #pragma GCC system_header
46 
47 #pragma GCC visibility push(default)
48 
49 #include <stddef.h>
50 #include <bits/cxxabi_tweaks.h>
51 #include <cxxabi-forced.h>
52 
53 #ifdef __cplusplus
54 #define _GLIBCXX_NOTHROW throw()
55 #else
56 #define _GLIBCXX_NOTHROW __attribute__((nothrow))
57 #endif
58 
59 #ifdef __cplusplus
60 namespace __cxxabiv1
61 {
62   extern "C"
63   {
64 #endif
65 
66   typedef __cxa_cdtor_return_type (*__cxa_cdtor_type)(void *);
67 
68   // Allocate array.
69   void*
70   __cxa_vec_new(size_t __element_count, size_t __element_size,
71 		size_t __padding_size, __cxa_cdtor_type constructor,
72 		__cxa_cdtor_type destructor);
73 
74   void*
75   __cxa_vec_new2(size_t __element_count, size_t __element_size,
76 		 size_t __padding_size, __cxa_cdtor_type constructor,
77 		 __cxa_cdtor_type destructor, void *(*__alloc) (size_t),
78 		 void (*__dealloc) (void*));
79 
80   void*
81   __cxa_vec_new3(size_t __element_count, size_t __element_size,
82 		 size_t __padding_size, __cxa_cdtor_type constructor,
83 		 __cxa_cdtor_type destructor, void *(*__alloc) (size_t),
84 		 void (*__dealloc) (void*, size_t));
85 
86   // Construct array.
87   __cxa_vec_ctor_return_type
88   __cxa_vec_ctor(void* __array_address, size_t __element_count,
89 		 size_t __element_size, __cxa_cdtor_type constructor,
90 		 __cxa_cdtor_type destructor);
91 
92   __cxa_vec_ctor_return_type
93   __cxa_vec_cctor(void* dest_array, void* src_array, size_t element_count,
94 		  size_t element_size,
95 		  __cxa_cdtor_return_type (*constructor) (void*, void*),
96 		  __cxa_cdtor_type destructor);
97 
98   // Destruct array.
99   void
100   __cxa_vec_dtor(void* __array_address, size_t __element_count,
101 		 size_t __element_size, __cxa_cdtor_type destructor);
102 
103   void
104   __cxa_vec_cleanup(void* __array_address, size_t __element_count,
105 		    size_t __s, __cxa_cdtor_type destructor) _GLIBCXX_NOTHROW;
106 
107   // Destruct and release array.
108   void
109   __cxa_vec_delete(void* __array_address, size_t __element_size,
110 		   size_t __padding_size, __cxa_cdtor_type destructor);
111 
112   void
113   __cxa_vec_delete2(void* __array_address, size_t __element_size,
114 		    size_t __padding_size, __cxa_cdtor_type destructor,
115 		    void (*__dealloc) (void*));
116 
117   void
118   __cxa_vec_delete3(void* __array_address, size_t __element_size,
119 		    size_t __padding_size, __cxa_cdtor_type destructor,
120 		    void (*__dealloc) (void*, size_t));
121 
122   int
123   __cxa_guard_acquire(__guard*);
124 
125   void
126   __cxa_guard_release(__guard*) _GLIBCXX_NOTHROW;
127 
128   void
129   __cxa_guard_abort(__guard*) _GLIBCXX_NOTHROW;
130 
131   // Pure virtual functions.
132   void
133   __cxa_pure_virtual(void) __attribute__ ((__noreturn__));
134 
135   // Exception handling.
136   void
137   __cxa_bad_cast();
138 
139   void
140   __cxa_bad_typeid();
141 
142   // DSO destruction.
143   int
144   __cxa_atexit(void (*)(void*), void*, void*) _GLIBCXX_NOTHROW;
145 
146   int
147   __cxa_finalize(void*);
148 
149 
150   /**
151    *  @brief Demangling routine.
152    *  ABI-mandated entry point in the C++ runtime library for demangling.
153    *
154    *  @param __mangled_name A NUL-terminated character string
155    *  containing the name to be demangled.
156    *
157    *  @param __output_buffer A region of memory, allocated with
158    *  malloc, of @a *__length bytes, into which the demangled name is
159    *  stored.  If @a __output_buffer is not long enough, it is
160    *  expanded using realloc.  @a __output_buffer may instead be NULL;
161    *  in that case, the demangled name is placed in a region of memory
162    *  allocated with malloc.
163    *
164    *  @param __length If @a __length is non-NULL, the length of the
165    *  buffer containing the demangled name is placed in @a *__length.
166    *
167    *  @param __status @a *__status is set to one of the following values:
168    *   0: The demangling operation succeeded.
169    *  -1: A memory allocation failure occurred.
170    *  -2: @a mangled_name is not a valid name under the C++ ABI mangling rules.
171    *  -3: One of the arguments is invalid.
172    *
173    *  @return A pointer to the start of the NUL-terminated demangled
174    *  name, or NULL if the demangling fails.  The caller is
175    *  responsible for deallocating this memory using @c free.
176    *
177    *  The demangling is performed using the C++ ABI mangling rules,
178    *  with GNU extensions. For example, this function is used in
179    *  __gnu_cxx::__verbose_terminate_handler.
180    *
181    *  See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch39.html
182    *  for other examples of use.
183    *
184    *  @note The same demangling functionality is available via
185    *  libiberty (@c <libiberty/demangle.h> and @c libiberty.a) in GCC
186    *  3.1 and later, but that requires explicit installation (@c
187    *  --enable-install-libiberty) and uses a different API, although
188    *  the ABI is unchanged.
189    */
190   char*
191   __cxa_demangle(const char* __mangled_name, char* __output_buffer,
192 		 size_t* __length, int* __status);
193 #ifdef __cplusplus
194   }
195 } // namespace __cxxabiv1
196 #endif
197 
198 #ifdef __cplusplus
199 
200 #include <typeinfo>
201 
202 namespace __cxxabiv1
203 {
204   // Type information for int, float etc.
205   class __fundamental_type_info : public std::type_info
206   {
207   public:
208     explicit
209     __fundamental_type_info(const char* __n) : std::type_info(__n) { }
210 
211     virtual
212     ~__fundamental_type_info();
213   };
214 
215   // Type information for array objects.
216   class __array_type_info : public std::type_info
217   {
218   public:
219     explicit
220     __array_type_info(const char* __n) : std::type_info(__n) { }
221 
222     virtual
223     ~__array_type_info();
224   };
225 
226   // Type information for functions (both member and non-member).
227   class __function_type_info : public std::type_info
228   {
229   public:
230     explicit
231     __function_type_info(const char* __n) : std::type_info(__n) { }
232 
233     virtual
234     ~__function_type_info();
235 
236   protected:
237     // Implementation defined member function.
238     virtual bool
239     __is_function_p() const;
240   };
241 
242   // Type information for enumerations.
243   class __enum_type_info : public std::type_info
244   {
245   public:
246     explicit
247     __enum_type_info(const char* __n) : std::type_info(__n) { }
248 
249     virtual
250     ~__enum_type_info();
251   };
252 
253   // Common type information for simple pointers and pointers to member.
254   class __pbase_type_info : public std::type_info
255   {
256   public:
257     unsigned int 		__flags; // Qualification of the target object.
258     const std::type_info* 	__pointee; // Type of pointed to object.
259 
260     explicit
261     __pbase_type_info(const char* __n, int __quals,
262 		      const std::type_info* __type)
263     : std::type_info(__n), __flags(__quals), __pointee(__type)
264     { }
265 
266     virtual
267     ~__pbase_type_info();
268 
269     // Implementation defined type.
270     enum __masks
271       {
272 	__const_mask = 0x1,
273 	__volatile_mask = 0x2,
274 	__restrict_mask = 0x4,
275 	__incomplete_mask = 0x8,
276 	__incomplete_class_mask = 0x10
277       };
278 
279   protected:
280     __pbase_type_info(const __pbase_type_info&);
281 
282     __pbase_type_info&
283     operator=(const __pbase_type_info&);
284 
285     // Implementation defined member functions.
286     virtual bool
287     __do_catch(const std::type_info* __thr_type, void** __thr_obj,
288 	       unsigned int __outer) const;
289 
290     inline virtual bool
291     __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
292 		    unsigned __outer) const;
293   };
294 
295   // Type information for simple pointers.
296   class __pointer_type_info : public __pbase_type_info
297   {
298   public:
299     explicit
300     __pointer_type_info(const char* __n, int __quals,
301 			const std::type_info* __type)
302     : __pbase_type_info (__n, __quals, __type) { }
303 
304 
305     virtual
306     ~__pointer_type_info();
307 
308   protected:
309     // Implementation defined member functions.
310     virtual bool
311     __is_pointer_p() const;
312 
313     virtual bool
314     __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
315 		    unsigned __outer) const;
316   };
317 
318   class __class_type_info;
319 
320   // Type information for a pointer to member variable.
321   class __pointer_to_member_type_info : public __pbase_type_info
322   {
323   public:
324     __class_type_info* __context;   // Class of the member.
325 
326     explicit
327     __pointer_to_member_type_info(const char* __n, int __quals,
328 				  const std::type_info* __type,
329 				  __class_type_info* __klass)
330     : __pbase_type_info(__n, __quals, __type), __context(__klass) { }
331 
332     virtual
333     ~__pointer_to_member_type_info();
334 
335   protected:
336     __pointer_to_member_type_info(const __pointer_to_member_type_info&);
337 
338     __pointer_to_member_type_info&
339     operator=(const __pointer_to_member_type_info&);
340 
341     // Implementation defined member function.
342     virtual bool
343     __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj,
344 		    unsigned __outer) const;
345   };
346 
347   // Helper class for __vmi_class_type.
348   class __base_class_type_info
349   {
350   public:
351     const __class_type_info* 	__base_type;  // Base class type.
352     long 			__offset_flags;  // Offset and info.
353 
354     enum __offset_flags_masks
355       {
356 	__virtual_mask = 0x1,
357 	__public_mask = 0x2,
358 	__hwm_bit = 2,
359 	__offset_shift = 8          // Bits to shift offset.
360       };
361 
362     // Implementation defined member functions.
363     bool
364     __is_virtual_p() const
365     { return __offset_flags & __virtual_mask; }
366 
367     bool
368     __is_public_p() const
369     { return __offset_flags & __public_mask; }
370 
371     ptrdiff_t
372     __offset() const
373     {
374       // This shift, being of a signed type, is implementation
375       // defined. GCC implements such shifts as arithmetic, which is
376       // what we want.
377       return static_cast<ptrdiff_t>(__offset_flags) >> __offset_shift;
378     }
379   };
380 
381   // Type information for a class.
382   class __class_type_info : public std::type_info
383   {
384   public:
385     explicit
386     __class_type_info (const char *__n) : type_info(__n) { }
387 
388     virtual
389     ~__class_type_info ();
390 
391     // Implementation defined types.
392     // The type sub_kind tells us about how a base object is contained
393     // within a derived object. We often do this lazily, hence the
394     // UNKNOWN value. At other times we may use NOT_CONTAINED to mean
395     // not publicly contained.
396     enum __sub_kind
397       {
398 	// We have no idea.
399 	__unknown = 0,
400 
401 	// Not contained within us (in some circumstances this might
402 	// mean not contained publicly)
403 	__not_contained,
404 
405 	// Contained ambiguously.
406 	__contained_ambig,
407 
408 	// Via a virtual path.
409 	__contained_virtual_mask = __base_class_type_info::__virtual_mask,
410 
411 	// Via a public path.
412 	__contained_public_mask = __base_class_type_info::__public_mask,
413 
414 	// Contained within us.
415 	__contained_mask = 1 << __base_class_type_info::__hwm_bit,
416 
417 	__contained_private = __contained_mask,
418 	__contained_public = __contained_mask | __contained_public_mask
419       };
420 
421     struct __upcast_result;
422     struct __dyncast_result;
423 
424   protected:
425     // Implementation defined member functions.
426     virtual bool
427     __do_upcast(const __class_type_info* __dst_type, void**__obj_ptr) const;
428 
429     virtual bool
430     __do_catch(const type_info* __thr_type, void** __thr_obj,
431 	       unsigned __outer) const;
432 
433   public:
434     // Helper for upcast. See if DST is us, or one of our bases.
435     // Return false if not found, true if found.
436     virtual bool
437     __do_upcast(const __class_type_info* __dst, const void* __obj,
438 		__upcast_result& __restrict __result) const;
439 
440     // Indicate whether SRC_PTR of type SRC_TYPE is contained publicly
441     // within OBJ_PTR. OBJ_PTR points to a base object of our type,
442     // which is the destination type. SRC2DST indicates how SRC
443     // objects might be contained within this type.  If SRC_PTR is one
444     // of our SRC_TYPE bases, indicate the virtuality. Returns
445     // not_contained for non containment or private containment.
446     inline __sub_kind
447     __find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
448 		      const __class_type_info* __src_type,
449 		      const void* __src_ptr) const;
450 
451     // Helper for dynamic cast. ACCESS_PATH gives the access from the
452     // most derived object to this base. DST_TYPE indicates the
453     // desired type we want. OBJ_PTR points to a base of our type
454     // within the complete object. SRC_TYPE indicates the static type
455     // started from and SRC_PTR points to that base within the most
456     // derived object. Fill in RESULT with what we find. Return true
457     // if we have located an ambiguous match.
458     virtual bool
459     __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
460 		 const __class_type_info* __dst_type, const void* __obj_ptr,
461 		 const __class_type_info* __src_type, const void* __src_ptr,
462 		 __dyncast_result& __result) const;
463 
464     // Helper for find_public_subobj. SRC2DST indicates how SRC_TYPE
465     // bases are inherited by the type started from -- which is not
466     // necessarily the current type. The current type will be a base
467     // of the destination type.  OBJ_PTR points to the current base.
468     virtual __sub_kind
469     __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
470 			 const __class_type_info* __src_type,
471 			 const void* __src_ptr) const;
472   };
473 
474   // Type information for a class with a single non-virtual base.
475   class __si_class_type_info : public __class_type_info
476   {
477   public:
478     const __class_type_info* __base_type;
479 
480     explicit
481     __si_class_type_info(const char *__n, const __class_type_info *__base)
482     : __class_type_info(__n), __base_type(__base) { }
483 
484     virtual
485     ~__si_class_type_info();
486 
487   protected:
488     __si_class_type_info(const __si_class_type_info&);
489 
490     __si_class_type_info&
491     operator=(const __si_class_type_info&);
492 
493     // Implementation defined member functions.
494     virtual bool
495     __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
496 		 const __class_type_info* __dst_type, const void* __obj_ptr,
497 		 const __class_type_info* __src_type, const void* __src_ptr,
498 		 __dyncast_result& __result) const;
499 
500     virtual __sub_kind
501     __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
502 			 const __class_type_info* __src_type,
503 			 const void* __sub_ptr) const;
504 
505     virtual bool
506     __do_upcast(const __class_type_info*__dst, const void*__obj,
507 		__upcast_result& __restrict __result) const;
508   };
509 
510   // Type information for a class with multiple and/or virtual bases.
511   class __vmi_class_type_info : public __class_type_info
512   {
513   public:
514     unsigned int 		__flags;  // Details about the class hierarchy.
515     unsigned int 		__base_count;  // Number of direct bases.
516 
517     // The array of bases uses the trailing array struct hack so this
518     // class is not constructable with a normal constructor. It is
519     // internally generated by the compiler.
520     __base_class_type_info 	__base_info[1];  // Array of bases.
521 
522     explicit
523     __vmi_class_type_info(const char* __n, int ___flags)
524     : __class_type_info(__n), __flags(___flags), __base_count(0) { }
525 
526     virtual
527     ~__vmi_class_type_info();
528 
529     // Implementation defined types.
530     enum __flags_masks
531       {
532 	__non_diamond_repeat_mask = 0x1, // Distinct instance of repeated base.
533 	__diamond_shaped_mask = 0x2, // Diamond shaped multiple inheritance.
534 	__flags_unknown_mask = 0x10
535       };
536 
537   protected:
538     // Implementation defined member functions.
539     virtual bool
540     __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path,
541 		 const __class_type_info* __dst_type, const void* __obj_ptr,
542 		 const __class_type_info* __src_type, const void* __src_ptr,
543 		 __dyncast_result& __result) const;
544 
545     virtual __sub_kind
546     __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr,
547 			 const __class_type_info* __src_type,
548 			 const void* __src_ptr) const;
549 
550     virtual bool
551     __do_upcast(const __class_type_info* __dst, const void* __obj,
552 		__upcast_result& __restrict __result) const;
553   };
554 
555   // Dynamic cast runtime.
556   // src2dst has the following possible values
557   //  >-1: src_type is a unique public non-virtual base of dst_type
558   //       dst_ptr + src2dst == src_ptr
559   //   -1: unspecified relationship
560   //   -2: src_type is not a public base of dst_type
561   //   -3: src_type is a multiple public non-virtual base of dst_type
562   extern "C" void*
563   __dynamic_cast(const void* __src_ptr, // Starting object.
564 		 const __class_type_info* __src_type, // Static type of object.
565 		 const __class_type_info* __dst_type, // Desired target type.
566 		 ptrdiff_t __src2dst); // How src and dst are related.
567 
568 
569   // Returns the type_info for the currently handled exception [15.3/8], or
570   // null if there is none.
571   extern "C" std::type_info*
572   __cxa_current_exception_type() _GLIBCXX_NOTHROW __attribute__ ((__pure__));
573 
574   // A magic placeholder class that can be caught by reference
575   // to recognize foreign exceptions.
576   class __foreign_exception
577   {
578     virtual ~__foreign_exception() _GLIBCXX_NOTHROW;
579     virtual void __pure_dummy() = 0; // prevent catch by value
580   };
581 
582 } // namespace __cxxabiv1
583 
584 /** @namespace abi
585  *  @brief The cross-vendor C++ Application Binary Interface. A
586  *  namespace alias to __cxxabiv1, but user programs should use the
587  *  alias 'abi'.
588  *
589  *  A brief overview of an ABI is given in the libstdc++ FAQ, question
590  *  5.8 (you may have a copy of the FAQ locally, or you can view the online
591  *  version at http://gcc.gnu.org/onlinedocs/libstdc++/faq/index.html#5_8).
592  *
593  *  GCC subscribes to a cross-vendor ABI for C++, sometimes
594  *  called the IA64 ABI because it happens to be the native ABI for that
595  *  platform.  It is summarized at http://www.codesourcery.com/cxx-abi/
596  *  along with the current specification.
597  *
598  *  For users of GCC greater than or equal to 3.x, entry points are
599  *  available in <cxxabi.h>, which notes, <em>'It is not normally
600  *  necessary for user programs to include this header, or use the
601  *  entry points directly.  However, this header is available should
602  *  that be needed.'</em>
603 */
604 namespace abi = __cxxabiv1;
605 
606 namespace __gnu_cxx
607 {
608   /**
609    *  @brief Exception thrown by __cxa_guard_acquire.
610    *  @ingroup exceptions
611    *
612    *  6.7[stmt.dcl]/4: If control re-enters the declaration (recursively)
613    *  while the object is being initialized, the behavior is undefined.
614    *
615    *  Since we already have a library function to handle locking, we might
616    *  as well check for this situation and throw an exception.
617    *  We use the second byte of the guard variable to remember that we're
618    *  in the middle of an initialization.
619    */
620   class recursive_init_error: public std::exception
621   {
622   public:
623     recursive_init_error() throw() { }
624     virtual ~recursive_init_error() throw ();
625   };
626 }
627 #endif // __cplusplus
628 
629 #pragma GCC visibility pop
630 
631 #endif // __CXXABI_H
632