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1 | 13 | up20180614 | /*
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2 | * Copyright 2012 David Chisnall. All rights reserved.
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3 | *
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4 | * Permission is hereby granted, free of charge, to any person obtaining a copy
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5 | * of this software and associated documentation files (the "Software"), to
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6 | * deal in the Software without restriction, including without limitation the
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7 | * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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8 | * sell copies of the Software, and to permit persons to whom the Software is
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9 | * furnished to do so, subject to the following conditions:
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10 | *
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11 | * The above copyright notice and this permission notice shall be
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12 | * included in all copies or substantial portions of the Software.
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13 | *
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14 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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15 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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16 | * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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17 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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18 | * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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19 | * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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20 | * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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21 | */
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22 | |||
23 | #ifndef __CXXABI_H_
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24 | #define __CXXABI_H_
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25 | #include <stddef.h> |
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26 | #include <stdint.h> |
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27 | #include "unwind.h" |
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28 | namespace std |
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29 | { |
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30 | class type_info; |
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31 | } |
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32 | /*
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33 | * The cxxabi.h header provides a set of public definitions for types and
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34 | * functions defined by the Itanium C++ ABI specification. For reference, see
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35 | * the ABI specification here:
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36 | *
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37 | * http://sourcery.mentor.com/public/cxx-abi/abi.html
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38 | *
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39 | * All deviations from this specification, unless otherwise noted, are
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40 | * accidental.
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41 | */
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42 | |||
43 | #ifdef __cplusplus
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44 | namespace __cxxabiv1 { |
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45 | extern "C" { |
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46 | #endif
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47 | /**
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48 | * Function type to call when an unexpected exception is encountered.
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49 | */
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50 | typedef void (*unexpected_handler)(); |
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51 | /**
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52 | * Function type to call when an unrecoverable condition is encountered.
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53 | */
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54 | typedef void (*terminate_handler)(); |
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55 | |||
56 | |||
57 | /**
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58 | * Structure used as a header on thrown exceptions. This is the same layout as
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59 | * defined by the Itanium ABI spec, so should be interoperable with any other
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60 | * implementation of this spec, such as GNU libsupc++.
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61 | *
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62 | * This structure is allocated when an exception is thrown. Unwinding happens
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63 | * in two phases, the first looks for a handler and the second installs the
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64 | * context. This structure stores a cache of the handler location between
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65 | * phase 1 and phase 2. Unfortunately, cleanup information is not cached, so
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66 | * must be looked up in both phases. This happens for two reasons. The first
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67 | * is that we don't know how many frames containing cleanups there will be, and
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68 | * we should avoid dynamic allocation during unwinding (the exception may be
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69 | * reporting that we've run out of memory). The second is that finding
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70 | * cleanups is much cheaper than finding handlers, because we don't have to
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71 | * look at the type table at all.
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72 | *
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73 | * Note: Several fields of this structure have not-very-informative names.
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74 | * These are taken from the ABI spec and have not been changed to make it
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75 | * easier for people referring to to the spec while reading this code.
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76 | */
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77 | struct __cxa_exception
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78 | { |
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79 | #if __LP64__
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80 | /**
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81 | * Reference count. Used to support the C++11 exception_ptr class. This
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82 | * is prepended to the structure in 64-bit mode and squeezed in to the
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83 | * padding left before the 64-bit aligned _Unwind_Exception at the end in
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84 | * 32-bit mode.
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85 | *
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86 | * Note that it is safe to extend this structure at the beginning, rather
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87 | * than the end, because the public API for creating it returns the address
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88 | * of the end (where the exception object can be stored).
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89 | */
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90 | uintptr_t referenceCount; |
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91 | #endif
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92 | /** Type info for the thrown object. */
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93 | std::type_info *exceptionType; |
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94 | /** Destructor for the object, if one exists. */
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95 | void (*exceptionDestructor) (void *); |
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96 | /** Handler called when an exception specification is violated. */
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97 | unexpected_handler unexpectedHandler; |
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98 | /** Hander called to terminate. */
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99 | terminate_handler terminateHandler; |
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100 | /**
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101 | * Next exception in the list. If an exception is thrown inside a catch
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102 | * block and caught in a nested catch, this points to the exception that
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103 | * will be handled after the inner catch block completes.
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104 | */
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105 | __cxa_exception *nextException; |
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106 | /**
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107 | * The number of handlers that currently have references to this
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108 | * exception. The top (non-sign) bit of this is used as a flag to indicate
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109 | * that the exception is being rethrown, so should not be deleted when its
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110 | * handler count reaches 0 (which it doesn't with the top bit set).
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111 | */
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112 | int handlerCount;
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113 | #if defined(__arm__) && !defined(__ARM_DWARF_EH__)
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114 | /**
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115 | * The ARM EH ABI requires the unwind library to keep track of exceptions
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116 | * during cleanups. These support nesting, so we need to keep a list of
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117 | * them.
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118 | */
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119 | _Unwind_Exception *nextCleanup; |
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120 | /**
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121 | * The number of cleanups that are currently being run on this exception.
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122 | */
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123 | int cleanupCount;
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124 | #endif
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125 | /**
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126 | * The selector value to be returned when installing the catch handler.
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127 | * Used at the call site to determine which catch() block should execute.
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128 | * This is found in phase 1 of unwinding then installed in phase 2.
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129 | */
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130 | int handlerSwitchValue;
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131 | /**
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132 | * The action record for the catch. This is cached during phase 1
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133 | * unwinding.
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134 | */
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135 | const char *actionRecord; |
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136 | /**
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137 | * Pointer to the language-specific data area (LSDA) for the handler
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138 | * frame. This is unused in this implementation, but set for ABI
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139 | * compatibility in case we want to mix code in very weird ways.
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140 | */
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141 | const char *languageSpecificData; |
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142 | /** The cached landing pad for the catch handler.*/
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143 | void *catchTemp;
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144 | /**
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145 | * The pointer that will be returned as the pointer to the object. When
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146 | * throwing a class and catching a virtual superclass (for example), we
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147 | * need to adjust the thrown pointer to make it all work correctly.
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148 | */
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149 | void *adjustedPtr;
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150 | #if !__LP64__
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151 | /**
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152 | * Reference count. Used to support the C++11 exception_ptr class. This
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153 | * is prepended to the structure in 64-bit mode and squeezed in to the
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154 | * padding left before the 64-bit aligned _Unwind_Exception at the end in
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155 | * 32-bit mode.
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156 | *
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157 | * Note that it is safe to extend this structure at the beginning, rather
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158 | * than the end, because the public API for creating it returns the address
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159 | * of the end (where the exception object can be stored)
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160 | */
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161 | uintptr_t referenceCount; |
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162 | #endif
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163 | /** The language-agnostic part of the exception header. */
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164 | _Unwind_Exception unwindHeader; |
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165 | }; |
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166 | |||
167 | /**
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168 | * ABI-specified globals structure. Returned by the __cxa_get_globals()
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169 | * function and its fast variant. This is a per-thread structure - every
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170 | * thread will have one lazily allocated.
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171 | *
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172 | * This structure is defined by the ABI, so may be used outside of this
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173 | * library.
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174 | */
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175 | struct __cxa_eh_globals
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176 | { |
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177 | /**
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178 | * A linked list of exceptions that are currently caught. There may be
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179 | * several of these in nested catch() blocks.
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180 | */
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181 | __cxa_exception *caughtExceptions; |
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182 | /**
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183 | * The number of uncaught exceptions.
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184 | */
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185 | unsigned int uncaughtExceptions; |
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186 | }; |
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187 | /**
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188 | * ABI function returning the __cxa_eh_globals structure.
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189 | */
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190 | __cxa_eh_globals *__cxa_get_globals(void);
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191 | /**
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192 | * Version of __cxa_get_globals() assuming that __cxa_get_globals() has already
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193 | * been called at least once by this thread.
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194 | */
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195 | __cxa_eh_globals *__cxa_get_globals_fast(void);
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196 | |||
197 | std::type_info * __cxa_current_exception_type(); |
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198 | |||
199 | /**
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200 | * Throws an exception returned by __cxa_current_primary_exception(). This
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201 | * exception may have been caught in another thread.
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202 | */
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203 | void __cxa_rethrow_primary_exception(void* thrown_exception); |
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204 | /**
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205 | * Returns the current exception in a form that can be stored in an
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206 | * exception_ptr object and then rethrown by a call to
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207 | * __cxa_rethrow_primary_exception().
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208 | */
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209 | void *__cxa_current_primary_exception(void); |
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210 | /**
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211 | * Increments the reference count of an exception. Called when an
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212 | * exception_ptr is copied.
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213 | */
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214 | void __cxa_increment_exception_refcount(void* thrown_exception); |
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215 | /**
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216 | * Decrements the reference count of an exception. Called when an
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217 | * exception_ptr is deleted.
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218 | */
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219 | void __cxa_decrement_exception_refcount(void* thrown_exception); |
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220 | /**
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221 | * Demangles a C++ symbol or type name. The buffer, if non-NULL, must be
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222 | * allocated with malloc() and must be *n bytes or more long. This function
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223 | * may call realloc() on the value pointed to by buf, and will return the
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224 | * length of the string via *n.
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225 | *
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226 | * The value pointed to by status is set to one of the following:
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227 | *
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228 | * 0: success
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229 | * -1: memory allocation failure
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230 | * -2: invalid mangled name
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231 | * -3: invalid arguments
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232 | */
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233 | char* __cxa_demangle(const char* mangled_name, |
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234 | char* buf,
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235 | size_t* n, |
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236 | int* status);
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237 | #ifdef __cplusplus
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238 | } // extern "C"
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239 | } // namespace
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240 | |||
241 | namespace abi = __cxxabiv1; |
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242 | |||
243 | #endif /* __cplusplus */ |
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244 | #endif /* __CXXABI_H_ */ |