bridges/source/cpp_uno/gcc3_ios/unwind-cxx.h

   1 // -*- C++ -*- Exception handling and frame unwind runtime interface routines.
   2 // Copyright (C) 2001 Free Software Foundation, Inc.
   3 //
   4 // This file is part of GCC.
   5 //
   6 // GCC is free software; you can redistribute it and/or modify
   7 // it under the terms of the GNU General Public License as published by
   8 // the Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10 //
  11 // GCC is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15 //
  16 // You should have received a copy of the GNU General Public License
  17 // along with GCC; see the file COPYING.  If not, write to
  18 // the Free Software Foundation, 51 Franklin Street, Fifth Floor,
  19 // Boston, MA 02110-1301, USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 // This is derived from the C++ ABI for IA-64.  Where we diverge
  31 // for cross-architecture compatibility are noted with "@@@".
  32
  33 #ifndef _UNWIND_CXX_H
  34 #define _UNWIND_CXX_H 1
  35
  36 // Level 2: C++ ABI
  37
  38 #include <typeinfo>
  39 #include <exception>
  40
  41 #include <stddef.h>
  42 #include "unwind.h"
  43
  44
  45 typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
  46 typedef signed   _Unwind_Sword __attribute__((__mode__(__word__)));
  47 typedef unsigned _Unwind_Word __attribute__((__mode__(__word__)));
  48 typedef unsigned _Unwind_Ptr __attribute__((__mode__(__pointer__)));
  49 typedef unsigned _Unwind_Exception_Class __attribute__((__mode__(__DI__)));
  50 typedef unsigned _Unwind_Internal_Ptr __attribute__((__mode__(__pointer__)));
  51
  52 #pragma GCC visibility push(default)
  53
  54 namespace __cxxabiv1
  55 {
  56
  57 // A C++ exception object consists of a header, which is a wrapper around
  58 // an unwind object header with additional C++ specific information,
  59 // followed by the exception object itself.
  60
  61 struct __cxa_exception
  62 {
  63 #if __LP64__
  64         // This is a new field to support C++ 0x exception_ptr.
  65         // For binary compatibility it is at the start of this
  66         // struct which is prepended to the object thrown in
  67         // __cxa_allocate_exception.
  68   size_t referenceCount;
  69 #endif
  70   // Manage the exception object itself.
  71   std::type_info *exceptionType;
  72   void (*exceptionDestructor)(void *);
  73
  74   // The C++ standard has entertaining rules wrt calling set_terminate
  75   // and set_unexpected in the middle of the exception cleanup process.
  76   void (*unexpectedHandler)(); // std::unexpected_handler dropped from C++17
  77   std::terminate_handler terminateHandler;
  78
  79   // The caught exception stack threads through here.
  80   __cxa_exception *nextException;
  81
  82   // How many nested handlers have caught this exception.  A negated
  83   // value is a signal that this object has been rethrown.
  84   int handlerCount;
  85
  86 #ifdef __ARM_EABI_UNWINDER__
  87   // Stack of exceptions in cleanups.
  88   __cxa_exception* nextPropagatingException;
  89
  90   // The number of active cleanup handlers for this exception.
  91   int propagationCount;
  92 #else
  93   // Cache parsed handler data from the personality routine Phase 1
  94   // for Phase 2 and __cxa_call_unexpected.
  95   int handlerSwitchValue;
  96   const unsigned char *actionRecord;
  97   const unsigned char *languageSpecificData;
  98   _Unwind_Ptr catchTemp;
  99   void *adjustedPtr;
 100 #endif
 101 #if !__LP64__
 102         // This is a new field to support C++ 0x exception_ptr.
 103         // For binary compatibility it is placed where the compiler
 104         // previously adding padded to 64-bit align unwindHeader.
 105   size_t referenceCount;
 106 #endif
 107
 108   // The generic exception header.  Must be last.
 109   _Unwind_Exception unwindHeader;
 110 };
 111
 112 // Each thread in a C++ program has access to a __cxa_eh_globals object.
 113 struct __cxa_eh_globals
 114 {
 115   __cxa_exception *caughtExceptions;
 116   unsigned int uncaughtExceptions;
 117 #ifdef __ARM_EABI_UNWINDER__
 118   __cxa_exception* propagatingExceptions;
 119 #endif
 120 };
 121
 122
 123 // The __cxa_eh_globals for the current thread can be obtained by using
 124 // either of the following functions.  The "fast" version assumes at least
 125 // one prior call of __cxa_get_globals has been made from the current
 126 // thread, so no initialization is necessary.
 127 extern "C" __cxa_eh_globals *__cxa_get_globals () throw();
 128 extern "C" __cxa_eh_globals *__cxa_get_globals_fast () throw();
 129
 130 // Allocate memory for the exception plus the thrown object.
 131 extern "C" void *__cxa_allocate_exception(size_t thrown_size) throw();
 132
 133 // Free the space allocated for the exception.
 134 extern "C" void __cxa_free_exception(void *thrown_exception) throw();
 135
 136 #pragma GCC visibility push(hidden)
 137 extern "C" void *__cxa_allocate_dependent_exception() throw();
 138 extern "C" void __cxa_free_dependent_exception(void *thrown_exception) throw();
 139 #pragma GCC visibility pop
 140
 141 // Throw the exception.
 142 extern "C" void __cxa_throw (void *thrown_exception,
 143                              std::type_info *tinfo,
 144                              void (*dest) (void *))
 145      __attribute__((noreturn));
 146
 147 // Used to implement exception handlers.
 148 extern "C" void *__cxa_get_exception_ptr (void *) throw();
 149 extern "C" void *__cxa_begin_catch (void *) throw();
 150 extern "C" void __cxa_end_catch ();
 151 extern "C" void __cxa_rethrow () __attribute__((noreturn));
 152
 153 // These facilitate code generation for recurring situations.
 154 extern "C" void __cxa_bad_cast ();
 155 extern "C" void __cxa_bad_typeid ();
 156
 157 // @@@ These are not directly specified by the IA-64 C++ ABI.
 158
 159 // Handles re-checking the exception specification if unexpectedHandler
 160 // throws, and if bad_exception needs to be thrown.  Called from the
 161 // compiler.
 162 extern "C" void __cxa_call_unexpected (void *) __attribute__((noreturn));
 163 extern "C" void __cxa_call_terminate (void*) __attribute__((noreturn));
 164
 165 #ifdef __ARM_EABI_UNWINDER__
 166 // Arm EABI specified routines.
 167 typedef enum {
 168   ctm_failed = 0,
 169   ctm_succeeded = 1,
 170   ctm_succeeded_with_ptr_to_base = 2
 171 } __cxa_type_match_result;
 172 extern "C" bool __cxa_type_match(_Unwind_Exception*, const std::type_info*,
 173                                  bool, void**);
 174 extern "C" void __cxa_begin_cleanup (_Unwind_Exception*);
 175 extern "C" void __cxa_end_cleanup (void);
 176 #endif
 177
 178 // These are explicitly GNU C++ specific.
 179
 180 // Acquire the C++ exception header from the C++ object.
 181 static inline __cxa_exception *
 182 __get_exception_header_from_obj (void *ptr)
 183 {
 184   return reinterpret_cast<__cxa_exception *>(ptr) - 1;
 185 }
 186
 187 // Acquire the C++ exception header from the generic exception header.
 188 static inline __cxa_exception *
 189 __get_exception_header_from_ue (_Unwind_Exception *exc)
 190 {
 191   return reinterpret_cast<__cxa_exception *>(exc + 1) - 1;
 192 }
 193
 194 #ifdef __ARM_EABI_UNWINDER__
 195 static inline bool
 196 __is_gxx_exception_class(_Unwind_Exception_Class c)
 197 {
 198   // TODO: Take advantage of the fact that c will always be word aligned.
 199   return c[0] == 'G'
 200          && c[1] == 'N'
 201          && c[2] == 'U'
 202          && c[3] == 'C'
 203          && c[4] == 'C'
 204          && c[5] == '+'
 205          && c[6] == '+';
 206 }
 207
 208 static inline void
 209 __GXX_INIT_EXCEPTION_CLASS(_Unwind_Exception_Class c)
 210 {
 211   c[0] = 'G';
 212   c[1] = 'N';
 213   c[2] = 'U';
 214   c[3] = 'C';
 215   c[4] = 'C';
 216   c[5] = '+';
 217   c[6] = '+';
 218   c[7] = '\0';
 219 }
 220
 221 static inline void*
 222 __gxx_caught_object(_Unwind_Exception* eo)
 223 {
 224   return (void*)eo->barrier_cache.bitpattern[0];
 225 }
 226 #else // !__ARM_EABI_UNWINDER__
 227 // This is the exception class we report -- "GNUCC++\0".
 228 const _Unwind_Exception_Class __gxx_exception_class
 229 = ((((((((_Unwind_Exception_Class) 'G'
 230          << 8 | (_Unwind_Exception_Class) 'N')
 231         << 8 | (_Unwind_Exception_Class) 'U')
 232        << 8 | (_Unwind_Exception_Class) 'C')
 233       << 8 | (_Unwind_Exception_Class) 'C')
 234      << 8 | (_Unwind_Exception_Class) '+')
 235     << 8 | (_Unwind_Exception_Class) '+')
 236    << 8 | (_Unwind_Exception_Class) '\0');
 237
 238 static inline bool
 239 __is_gxx_exception_class(_Unwind_Exception_Class c)
 240 {
 241   return (c & ((_Unwind_Exception_Class)~0 << 8)) == __gxx_exception_class;
 242 }
 243
 244 #define __GXX_INIT_EXCEPTION_CLASS(c) c = __gxx_exception_class
 245
 246 // GNU C++ personality routine, Version 0.
 247 extern "C" _Unwind_Reason_Code __gxx_personality_v0
 248      (int, _Unwind_Action, _Unwind_Exception_Class,
 249       struct _Unwind_Exception *, struct _Unwind_Context *);
 250
 251 // GNU C++ sjlj personality routine, Version 0.
 252 extern "C" _Unwind_Reason_Code __gxx_personality_sj0
 253      (int, _Unwind_Action, _Unwind_Exception_Class,
 254       struct _Unwind_Exception *, struct _Unwind_Context *);
 255
 256 static inline void*
 257 __gxx_caught_object(_Unwind_Exception* eo)
 258 {
 259   __cxa_exception* header = __get_exception_header_from_ue (eo);
 260   return header->adjustedPtr;
 261 }
 262 #endif // !__ARM_EABI_UNWINDER__
 263
 264 } /* namespace __cxxabiv1 */
 265
 266 #pragma GCC visibility pop
 267
 268 #endif // _UNWIND_CXX_H