libstdc++
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00001 // ABI Support -*- C++ -*- 00002 00003 // Copyright (C) 2000-2016 Free Software Foundation, Inc. 00004 // 00005 // This file is part of GCC. 00006 // 00007 // GCC is free software; you can redistribute it and/or modify 00008 // it under the terms of the GNU General Public License as published by 00009 // the Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 // 00012 // GCC is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 // 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 // Written by Nathan Sidwell, Codesourcery LLC, <nathan@codesourcery.com> 00027 00028 /* This file declares the new abi entry points into the runtime. It is not 00029 normally necessary for user programs to include this header, or use the 00030 entry points directly. However, this header is available should that be 00031 needed. 00032 00033 Some of the entry points are intended for both C and C++, thus this header 00034 is includable from both C and C++. Though the C++ specific parts are not 00035 available in C, naturally enough. */ 00036 00037 /** @file cxxabi.h 00038 * The header provides an interface to the C++ ABI. 00039 */ 00040 00041 #ifndef _CXXABI_H 00042 #define _CXXABI_H 1 00043 00044 #pragma GCC system_header 00045 00046 #pragma GCC visibility push(default) 00047 00048 #include <stddef.h> 00049 #include <bits/c++config.h> 00050 #include <bits/cxxabi_tweaks.h> 00051 #include <bits/cxxabi_forced.h> 00052 00053 #ifndef _GLIBCXX_CDTOR_CALLABI 00054 #define _GLIBCXX_CDTOR_CALLABI 00055 #endif 00056 00057 #ifdef __cplusplus 00058 namespace __cxxabiv1 00059 { 00060 extern "C" 00061 { 00062 #endif 00063 00064 typedef __cxa_cdtor_return_type (*__cxa_cdtor_type)(void *); 00065 00066 // Allocate array. 00067 void* 00068 __cxa_vec_new(size_t __element_count, size_t __element_size, 00069 size_t __padding_size, __cxa_cdtor_type __constructor, 00070 __cxa_cdtor_type __destructor); 00071 00072 void* 00073 __cxa_vec_new2(size_t __element_count, size_t __element_size, 00074 size_t __padding_size, __cxa_cdtor_type __constructor, 00075 __cxa_cdtor_type __destructor, void *(*__alloc) (size_t), 00076 void (*__dealloc) (void*)); 00077 00078 void* 00079 __cxa_vec_new3(size_t __element_count, size_t __element_size, 00080 size_t __padding_size, __cxa_cdtor_type __constructor, 00081 __cxa_cdtor_type __destructor, void *(*__alloc) (size_t), 00082 void (*__dealloc) (void*, size_t)); 00083 00084 // Construct array. 00085 __cxa_vec_ctor_return_type 00086 __cxa_vec_ctor(void* __array_address, size_t __element_count, 00087 size_t __element_size, __cxa_cdtor_type __constructor, 00088 __cxa_cdtor_type __destructor); 00089 00090 __cxa_vec_ctor_return_type 00091 __cxa_vec_cctor(void* __dest_array, void* __src_array, 00092 size_t __element_count, size_t __element_size, 00093 __cxa_cdtor_return_type (*__constructor) (void*, void*), 00094 __cxa_cdtor_type __destructor); 00095 00096 // Destruct array. 00097 void 00098 __cxa_vec_dtor(void* __array_address, size_t __element_count, 00099 size_t __element_size, __cxa_cdtor_type __destructor); 00100 00101 void 00102 __cxa_vec_cleanup(void* __array_address, size_t __element_count, size_t __s, 00103 __cxa_cdtor_type __destructor) _GLIBCXX_NOTHROW; 00104 00105 // Destruct and release array. 00106 void 00107 __cxa_vec_delete(void* __array_address, size_t __element_size, 00108 size_t __padding_size, __cxa_cdtor_type __destructor); 00109 00110 void 00111 __cxa_vec_delete2(void* __array_address, size_t __element_size, 00112 size_t __padding_size, __cxa_cdtor_type __destructor, 00113 void (*__dealloc) (void*)); 00114 00115 void 00116 __cxa_vec_delete3(void* __array_address, size_t __element_size, 00117 size_t __padding_size, __cxa_cdtor_type __destructor, 00118 void (*__dealloc) (void*, size_t)); 00119 00120 int 00121 __cxa_guard_acquire(__guard*); 00122 00123 void 00124 __cxa_guard_release(__guard*) _GLIBCXX_NOTHROW; 00125 00126 void 00127 __cxa_guard_abort(__guard*) _GLIBCXX_NOTHROW; 00128 00129 // DSO destruction. 00130 int 00131 __cxa_atexit(void (*)(void*), void*, void*) _GLIBCXX_NOTHROW; 00132 00133 int 00134 __cxa_finalize(void*); 00135 00136 // TLS destruction. 00137 int 00138 __cxa_thread_atexit(void (*)(void*), void*, void *) _GLIBCXX_NOTHROW; 00139 00140 // Pure virtual functions. 00141 void 00142 __cxa_pure_virtual(void) __attribute__ ((__noreturn__)); 00143 00144 void 00145 __cxa_deleted_virtual(void) __attribute__ ((__noreturn__)); 00146 00147 // Exception handling auxiliary. 00148 void 00149 __cxa_bad_cast() __attribute__((__noreturn__)); 00150 00151 void 00152 __cxa_bad_typeid() __attribute__((__noreturn__)); 00153 00154 void 00155 __cxa_throw_bad_array_new_length() __attribute__((__noreturn__)); 00156 00157 /** 00158 * @brief Demangling routine. 00159 * ABI-mandated entry point in the C++ runtime library for demangling. 00160 * 00161 * @param __mangled_name A NUL-terminated character string 00162 * containing the name to be demangled. 00163 * 00164 * @param __output_buffer A region of memory, allocated with 00165 * malloc, of @a *__length bytes, into which the demangled name is 00166 * stored. If @a __output_buffer is not long enough, it is 00167 * expanded using realloc. @a __output_buffer may instead be NULL; 00168 * in that case, the demangled name is placed in a region of memory 00169 * allocated with malloc. 00170 * 00171 * @param __length If @a __length is non-NULL, the length of the 00172 * buffer containing the demangled name is placed in @a *__length. 00173 * 00174 * @param __status @a *__status is set to one of the following values: 00175 * 0: The demangling operation succeeded. 00176 * -1: A memory allocation failure occurred. 00177 * -2: @a mangled_name is not a valid name under the C++ ABI mangling rules. 00178 * -3: One of the arguments is invalid. 00179 * 00180 * @return A pointer to the start of the NUL-terminated demangled 00181 * name, or NULL if the demangling fails. The caller is 00182 * responsible for deallocating this memory using @c free. 00183 * 00184 * The demangling is performed using the C++ ABI mangling rules, 00185 * with GNU extensions. For example, this function is used in 00186 * __gnu_cxx::__verbose_terminate_handler. 00187 * 00188 * See http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt12ch39.html 00189 * for other examples of use. 00190 * 00191 * @note The same demangling functionality is available via 00192 * libiberty (@c <libiberty/demangle.h> and @c libiberty.a) in GCC 00193 * 3.1 and later, but that requires explicit installation (@c 00194 * --enable-install-libiberty) and uses a different API, although 00195 * the ABI is unchanged. 00196 */ 00197 char* 00198 __cxa_demangle(const char* __mangled_name, char* __output_buffer, 00199 size_t* __length, int* __status); 00200 00201 #ifdef __cplusplus 00202 } 00203 } // namespace __cxxabiv1 00204 #endif 00205 00206 #ifdef __cplusplus 00207 00208 #include <typeinfo> 00209 00210 namespace __cxxabiv1 00211 { 00212 // Type information for int, float etc. 00213 class __fundamental_type_info : public std::type_info 00214 { 00215 public: 00216 explicit 00217 __fundamental_type_info(const char* __n) : std::type_info(__n) { } 00218 00219 virtual 00220 ~__fundamental_type_info(); 00221 }; 00222 00223 // Type information for array objects. 00224 class __array_type_info : public std::type_info 00225 { 00226 public: 00227 explicit 00228 __array_type_info(const char* __n) : std::type_info(__n) { } 00229 00230 virtual 00231 ~__array_type_info(); 00232 }; 00233 00234 // Type information for functions (both member and non-member). 00235 class __function_type_info : public std::type_info 00236 { 00237 public: 00238 explicit 00239 __function_type_info(const char* __n) : std::type_info(__n) { } 00240 00241 virtual 00242 ~__function_type_info(); 00243 00244 protected: 00245 // Implementation defined member function. 00246 virtual bool 00247 __is_function_p() const; 00248 }; 00249 00250 // Type information for enumerations. 00251 class __enum_type_info : public std::type_info 00252 { 00253 public: 00254 explicit 00255 __enum_type_info(const char* __n) : std::type_info(__n) { } 00256 00257 virtual 00258 ~__enum_type_info(); 00259 }; 00260 00261 // Common type information for simple pointers and pointers to member. 00262 class __pbase_type_info : public std::type_info 00263 { 00264 public: 00265 unsigned int __flags; // Qualification of the target object. 00266 const std::type_info* __pointee; // Type of pointed to object. 00267 00268 explicit 00269 __pbase_type_info(const char* __n, int __quals, 00270 const std::type_info* __type) 00271 : std::type_info(__n), __flags(__quals), __pointee(__type) 00272 { } 00273 00274 virtual 00275 ~__pbase_type_info(); 00276 00277 // Implementation defined type. 00278 enum __masks 00279 { 00280 __const_mask = 0x1, 00281 __volatile_mask = 0x2, 00282 __restrict_mask = 0x4, 00283 __incomplete_mask = 0x8, 00284 __incomplete_class_mask = 0x10, 00285 __transaction_safe_mask = 0x20 00286 }; 00287 00288 protected: 00289 __pbase_type_info(const __pbase_type_info&); 00290 00291 __pbase_type_info& 00292 operator=(const __pbase_type_info&); 00293 00294 // Implementation defined member functions. 00295 virtual bool 00296 __do_catch(const std::type_info* __thr_type, void** __thr_obj, 00297 unsigned int __outer) const; 00298 00299 inline virtual bool 00300 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj, 00301 unsigned __outer) const; 00302 }; 00303 00304 inline bool __pbase_type_info:: 00305 __pointer_catch (const __pbase_type_info *thrown_type, 00306 void **thr_obj, 00307 unsigned outer) const 00308 { 00309 return __pointee->__do_catch (thrown_type->__pointee, thr_obj, outer + 2); 00310 } 00311 00312 // Type information for simple pointers. 00313 class __pointer_type_info : public __pbase_type_info 00314 { 00315 public: 00316 explicit 00317 __pointer_type_info(const char* __n, int __quals, 00318 const std::type_info* __type) 00319 : __pbase_type_info (__n, __quals, __type) { } 00320 00321 00322 virtual 00323 ~__pointer_type_info(); 00324 00325 protected: 00326 // Implementation defined member functions. 00327 virtual bool 00328 __is_pointer_p() const; 00329 00330 virtual bool 00331 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj, 00332 unsigned __outer) const; 00333 }; 00334 00335 class __class_type_info; 00336 00337 // Type information for a pointer to member variable. 00338 class __pointer_to_member_type_info : public __pbase_type_info 00339 { 00340 public: 00341 __class_type_info* __context; // Class of the member. 00342 00343 explicit 00344 __pointer_to_member_type_info(const char* __n, int __quals, 00345 const std::type_info* __type, 00346 __class_type_info* __klass) 00347 : __pbase_type_info(__n, __quals, __type), __context(__klass) { } 00348 00349 virtual 00350 ~__pointer_to_member_type_info(); 00351 00352 protected: 00353 __pointer_to_member_type_info(const __pointer_to_member_type_info&); 00354 00355 __pointer_to_member_type_info& 00356 operator=(const __pointer_to_member_type_info&); 00357 00358 // Implementation defined member function. 00359 virtual bool 00360 __pointer_catch(const __pbase_type_info* __thr_type, void** __thr_obj, 00361 unsigned __outer) const; 00362 }; 00363 00364 // Helper class for __vmi_class_type. 00365 class __base_class_type_info 00366 { 00367 public: 00368 const __class_type_info* __base_type; // Base class type. 00369 #ifdef _GLIBCXX_LLP64 00370 long long __offset_flags; // Offset and info. 00371 #else 00372 long __offset_flags; // Offset and info. 00373 #endif 00374 00375 enum __offset_flags_masks 00376 { 00377 __virtual_mask = 0x1, 00378 __public_mask = 0x2, 00379 __hwm_bit = 2, 00380 __offset_shift = 8 // Bits to shift offset. 00381 }; 00382 00383 // Implementation defined member functions. 00384 bool 00385 __is_virtual_p() const 00386 { return __offset_flags & __virtual_mask; } 00387 00388 bool 00389 __is_public_p() const 00390 { return __offset_flags & __public_mask; } 00391 00392 ptrdiff_t 00393 __offset() const 00394 { 00395 // This shift, being of a signed type, is implementation 00396 // defined. GCC implements such shifts as arithmetic, which is 00397 // what we want. 00398 return static_cast<ptrdiff_t>(__offset_flags) >> __offset_shift; 00399 } 00400 }; 00401 00402 // Type information for a class. 00403 class __class_type_info : public std::type_info 00404 { 00405 public: 00406 explicit 00407 __class_type_info (const char *__n) : type_info(__n) { } 00408 00409 virtual 00410 ~__class_type_info (); 00411 00412 // Implementation defined types. 00413 // The type sub_kind tells us about how a base object is contained 00414 // within a derived object. We often do this lazily, hence the 00415 // UNKNOWN value. At other times we may use NOT_CONTAINED to mean 00416 // not publicly contained. 00417 enum __sub_kind 00418 { 00419 // We have no idea. 00420 __unknown = 0, 00421 00422 // Not contained within us (in some circumstances this might 00423 // mean not contained publicly) 00424 __not_contained, 00425 00426 // Contained ambiguously. 00427 __contained_ambig, 00428 00429 // Via a virtual path. 00430 __contained_virtual_mask = __base_class_type_info::__virtual_mask, 00431 00432 // Via a public path. 00433 __contained_public_mask = __base_class_type_info::__public_mask, 00434 00435 // Contained within us. 00436 __contained_mask = 1 << __base_class_type_info::__hwm_bit, 00437 00438 __contained_private = __contained_mask, 00439 __contained_public = __contained_mask | __contained_public_mask 00440 }; 00441 00442 struct __upcast_result; 00443 struct __dyncast_result; 00444 00445 protected: 00446 // Implementation defined member functions. 00447 virtual bool 00448 __do_upcast(const __class_type_info* __dst_type, void**__obj_ptr) const; 00449 00450 virtual bool 00451 __do_catch(const type_info* __thr_type, void** __thr_obj, 00452 unsigned __outer) const; 00453 00454 public: 00455 // Helper for upcast. See if DST is us, or one of our bases. 00456 // Return false if not found, true if found. 00457 virtual bool 00458 __do_upcast(const __class_type_info* __dst, const void* __obj, 00459 __upcast_result& __restrict __result) const; 00460 00461 // Indicate whether SRC_PTR of type SRC_TYPE is contained publicly 00462 // within OBJ_PTR. OBJ_PTR points to a base object of our type, 00463 // which is the destination type. SRC2DST indicates how SRC 00464 // objects might be contained within this type. If SRC_PTR is one 00465 // of our SRC_TYPE bases, indicate the virtuality. Returns 00466 // not_contained for non containment or private containment. 00467 inline __sub_kind 00468 __find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr, 00469 const __class_type_info* __src_type, 00470 const void* __src_ptr) const; 00471 00472 // Helper for dynamic cast. ACCESS_PATH gives the access from the 00473 // most derived object to this base. DST_TYPE indicates the 00474 // desired type we want. OBJ_PTR points to a base of our type 00475 // within the complete object. SRC_TYPE indicates the static type 00476 // started from and SRC_PTR points to that base within the most 00477 // derived object. Fill in RESULT with what we find. Return true 00478 // if we have located an ambiguous match. 00479 virtual bool 00480 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path, 00481 const __class_type_info* __dst_type, const void* __obj_ptr, 00482 const __class_type_info* __src_type, const void* __src_ptr, 00483 __dyncast_result& __result) const; 00484 00485 // Helper for find_public_subobj. SRC2DST indicates how SRC_TYPE 00486 // bases are inherited by the type started from -- which is not 00487 // necessarily the current type. The current type will be a base 00488 // of the destination type. OBJ_PTR points to the current base. 00489 virtual __sub_kind 00490 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr, 00491 const __class_type_info* __src_type, 00492 const void* __src_ptr) const; 00493 }; 00494 00495 // Type information for a class with a single non-virtual base. 00496 class __si_class_type_info : public __class_type_info 00497 { 00498 public: 00499 const __class_type_info* __base_type; 00500 00501 explicit 00502 __si_class_type_info(const char *__n, const __class_type_info *__base) 00503 : __class_type_info(__n), __base_type(__base) { } 00504 00505 virtual 00506 ~__si_class_type_info(); 00507 00508 protected: 00509 __si_class_type_info(const __si_class_type_info&); 00510 00511 __si_class_type_info& 00512 operator=(const __si_class_type_info&); 00513 00514 // Implementation defined member functions. 00515 virtual bool 00516 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path, 00517 const __class_type_info* __dst_type, const void* __obj_ptr, 00518 const __class_type_info* __src_type, const void* __src_ptr, 00519 __dyncast_result& __result) const; 00520 00521 virtual __sub_kind 00522 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr, 00523 const __class_type_info* __src_type, 00524 const void* __sub_ptr) const; 00525 00526 virtual bool 00527 __do_upcast(const __class_type_info*__dst, const void*__obj, 00528 __upcast_result& __restrict __result) const; 00529 }; 00530 00531 // Type information for a class with multiple and/or virtual bases. 00532 class __vmi_class_type_info : public __class_type_info 00533 { 00534 public: 00535 unsigned int __flags; // Details about the class hierarchy. 00536 unsigned int __base_count; // Number of direct bases. 00537 00538 // The array of bases uses the trailing array struct hack so this 00539 // class is not constructable with a normal constructor. It is 00540 // internally generated by the compiler. 00541 __base_class_type_info __base_info[1]; // Array of bases. 00542 00543 explicit 00544 __vmi_class_type_info(const char* __n, int ___flags) 00545 : __class_type_info(__n), __flags(___flags), __base_count(0) { } 00546 00547 virtual 00548 ~__vmi_class_type_info(); 00549 00550 // Implementation defined types. 00551 enum __flags_masks 00552 { 00553 __non_diamond_repeat_mask = 0x1, // Distinct instance of repeated base. 00554 __diamond_shaped_mask = 0x2, // Diamond shaped multiple inheritance. 00555 __flags_unknown_mask = 0x10 00556 }; 00557 00558 protected: 00559 // Implementation defined member functions. 00560 virtual bool 00561 __do_dyncast(ptrdiff_t __src2dst, __sub_kind __access_path, 00562 const __class_type_info* __dst_type, const void* __obj_ptr, 00563 const __class_type_info* __src_type, const void* __src_ptr, 00564 __dyncast_result& __result) const; 00565 00566 virtual __sub_kind 00567 __do_find_public_src(ptrdiff_t __src2dst, const void* __obj_ptr, 00568 const __class_type_info* __src_type, 00569 const void* __src_ptr) const; 00570 00571 virtual bool 00572 __do_upcast(const __class_type_info* __dst, const void* __obj, 00573 __upcast_result& __restrict __result) const; 00574 }; 00575 00576 // Exception handling forward declarations. 00577 struct __cxa_exception; 00578 struct __cxa_refcounted_exception; 00579 struct __cxa_dependent_exception; 00580 struct __cxa_eh_globals; 00581 00582 extern "C" 00583 { 00584 // Dynamic cast runtime. 00585 00586 // src2dst has the following possible values 00587 // >-1: src_type is a unique public non-virtual base of dst_type 00588 // dst_ptr + src2dst == src_ptr 00589 // -1: unspecified relationship 00590 // -2: src_type is not a public base of dst_type 00591 // -3: src_type is a multiple public non-virtual base of dst_type 00592 void* 00593 __dynamic_cast(const void* __src_ptr, // Starting object. 00594 const __class_type_info* __src_type, // Static type of object. 00595 const __class_type_info* __dst_type, // Desired target type. 00596 ptrdiff_t __src2dst); // How src and dst are related. 00597 00598 00599 // Exception handling runtime. 00600 00601 // The __cxa_eh_globals for the current thread can be obtained by using 00602 // either of the following functions. The "fast" version assumes at least 00603 // one prior call of __cxa_get_globals has been made from the current 00604 // thread, so no initialization is necessary. 00605 __cxa_eh_globals* 00606 __cxa_get_globals() _GLIBCXX_NOTHROW __attribute__ ((__const__)); 00607 00608 __cxa_eh_globals* 00609 __cxa_get_globals_fast() _GLIBCXX_NOTHROW __attribute__ ((__const__)); 00610 00611 // Allocate memory for the primary exception plus the thrown object. 00612 void* 00613 __cxa_allocate_exception(size_t) _GLIBCXX_NOTHROW; 00614 00615 // Free the space allocated for the primary exception. 00616 void 00617 __cxa_free_exception(void*) _GLIBCXX_NOTHROW; 00618 00619 // Throw the exception. 00620 void 00621 __cxa_throw(void*, std::type_info*, void (_GLIBCXX_CDTOR_CALLABI *) (void *)) 00622 __attribute__((__noreturn__)); 00623 00624 // Used to implement exception handlers. 00625 void* 00626 __cxa_get_exception_ptr(void*) _GLIBCXX_NOTHROW __attribute__ ((__pure__)); 00627 00628 void* 00629 __cxa_begin_catch(void*) _GLIBCXX_NOTHROW; 00630 00631 void 00632 __cxa_end_catch(); 00633 00634 void 00635 __cxa_rethrow() __attribute__((__noreturn__)); 00636 00637 // Returns the type_info for the currently handled exception [15.3/8], or 00638 // null if there is none. 00639 std::type_info* 00640 __cxa_current_exception_type() _GLIBCXX_NOTHROW __attribute__ ((__pure__)); 00641 00642 // GNU Extensions. 00643 00644 // Allocate memory for a dependent exception. 00645 __cxa_dependent_exception* 00646 __cxa_allocate_dependent_exception() _GLIBCXX_NOTHROW; 00647 00648 // Free the space allocated for the dependent exception. 00649 void 00650 __cxa_free_dependent_exception(__cxa_dependent_exception*) _GLIBCXX_NOTHROW; 00651 00652 } // extern "C" 00653 00654 // A magic placeholder class that can be caught by reference 00655 // to recognize foreign exceptions. 00656 class __foreign_exception 00657 { 00658 virtual ~__foreign_exception() throw(); 00659 virtual void __pure_dummy() = 0; // prevent catch by value 00660 }; 00661 00662 } // namespace __cxxabiv1 00663 00664 /** @namespace abi 00665 * @brief The cross-vendor C++ Application Binary Interface. A 00666 * namespace alias to __cxxabiv1, but user programs should use the 00667 * alias 'abi'. 00668 * 00669 * A brief overview of an ABI is given in the libstdc++ FAQ, question 00670 * 5.8 (you may have a copy of the FAQ locally, or you can view the online 00671 * version at http://gcc.gnu.org/onlinedocs/libstdc++/faq.html#5_8 ). 00672 * 00673 * GCC subscribes to a cross-vendor ABI for C++, sometimes 00674 * called the IA64 ABI because it happens to be the native ABI for that 00675 * platform. It is summarized at http://www.codesourcery.com/cxx-abi/ 00676 * along with the current specification. 00677 * 00678 * For users of GCC greater than or equal to 3.x, entry points are 00679 * available in <cxxabi.h>, which notes, <em>'It is not normally 00680 * necessary for user programs to include this header, or use the 00681 * entry points directly. However, this header is available should 00682 * that be needed.'</em> 00683 */ 00684 namespace abi = __cxxabiv1; 00685 00686 namespace __gnu_cxx 00687 { 00688 /** 00689 * @brief Exception thrown by __cxa_guard_acquire. 00690 * @ingroup exceptions 00691 * 00692 * 6.7[stmt.dcl]/4: If control re-enters the declaration (recursively) 00693 * while the object is being initialized, the behavior is undefined. 00694 * 00695 * Since we already have a library function to handle locking, we might 00696 * as well check for this situation and throw an exception. 00697 * We use the second byte of the guard variable to remember that we're 00698 * in the middle of an initialization. 00699 */ 00700 class recursive_init_error: public std::exception 00701 { 00702 public: 00703 recursive_init_error() throw() { } 00704 virtual ~recursive_init_error() throw (); 00705 }; 00706 } 00707 #endif // __cplusplus 00708 00709 #pragma GCC visibility pop 00710 00711 #endif // __CXXABI_H