1 //===-------------------------- cxa_vector.cpp ---------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 // 9 // This file implements the "Array Construction and Destruction APIs" 10 // http://mentorembedded.github.io/cxx-abi/abi.html#array-ctor 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "cxxabi.h" 15 16 #include <exception> // for std::terminate 17 18 namespace __cxxabiv1 { 19 20 #if 0 21 #pragma mark --Helper routines and classes -- 22 #endif 23 24 namespace { 25 inline static size_t __get_element_count ( void *p ) { 26 return static_cast <size_t *> (p)[-1]; 27 } 28 29 inline static void __set_element_count ( void *p, size_t element_count ) { 30 static_cast <size_t *> (p)[-1] = element_count; 31 } 32 33 34 // A pair of classes to simplify exception handling and control flow. 35 // They get passed a block of memory in the constructor, and unless the 36 // 'release' method is called, they deallocate the memory in the destructor. 37 // Preferred usage is to allocate some memory, attach it to one of these objects, 38 // and then, when all the operations to set up the memory block have succeeded, 39 // call 'release'. If any of the setup operations fail, or an exception is 40 // thrown, then the block is automatically deallocated. 41 // 42 // The only difference between these two classes is the signature for the 43 // deallocation function (to match new2/new3 and delete2/delete3. 44 class st_heap_block2 { 45 public: 46 typedef void (*dealloc_f)(void *); 47 48 st_heap_block2 ( dealloc_f dealloc, void *ptr ) 49 : dealloc_ ( dealloc ), ptr_ ( ptr ), enabled_ ( true ) {} 50 ~st_heap_block2 () { if ( enabled_ ) dealloc_ ( ptr_ ) ; } 51 void release () { enabled_ = false; } 52 53 private: 54 dealloc_f dealloc_; 55 void *ptr_; 56 bool enabled_; 57 }; 58 59 class st_heap_block3 { 60 public: 61 typedef void (*dealloc_f)(void *, size_t); 62 63 st_heap_block3 ( dealloc_f dealloc, void *ptr, size_t size ) 64 : dealloc_ ( dealloc ), ptr_ ( ptr ), size_ ( size ), enabled_ ( true ) {} 65 ~st_heap_block3 () { if ( enabled_ ) dealloc_ ( ptr_, size_ ) ; } 66 void release () { enabled_ = false; } 67 68 private: 69 dealloc_f dealloc_; 70 void *ptr_; 71 size_t size_; 72 bool enabled_; 73 }; 74 75 class st_cxa_cleanup { 76 public: 77 typedef void (*destruct_f)(void *); 78 79 st_cxa_cleanup ( void *ptr, size_t &idx, size_t element_size, destruct_f destructor ) 80 : ptr_ ( ptr ), idx_ ( idx ), element_size_ ( element_size ), 81 destructor_ ( destructor ), enabled_ ( true ) {} 82 ~st_cxa_cleanup () { 83 if ( enabled_ ) 84 __cxa_vec_cleanup ( ptr_, idx_, element_size_, destructor_ ); 85 } 86 87 void release () { enabled_ = false; } 88 89 private: 90 void *ptr_; 91 size_t &idx_; 92 size_t element_size_; 93 destruct_f destructor_; 94 bool enabled_; 95 }; 96 97 class st_terminate { 98 public: 99 st_terminate ( bool enabled = true ) : enabled_ ( enabled ) {} 100 ~st_terminate () { if ( enabled_ ) std::terminate (); } 101 void release () { enabled_ = false; } 102 private: 103 bool enabled_ ; 104 }; 105 } 106 107 #if 0 108 #pragma mark --Externally visible routines-- 109 #endif 110 111 extern "C" { 112 113 // Equivalent to 114 // 115 // __cxa_vec_new2(element_count, element_size, padding_size, constructor, 116 // destructor, &::operator new[], &::operator delete[]) 117 _LIBCXXABI_FUNC_VIS void * 118 __cxa_vec_new(size_t element_count, size_t element_size, size_t padding_size, 119 void (*constructor)(void *), void (*destructor)(void *)) { 120 return __cxa_vec_new2 ( element_count, element_size, padding_size, 121 constructor, destructor, &::operator new [], &::operator delete [] ); 122 } 123 124 125 126 // Given the number and size of elements for an array and the non-negative 127 // size of prefix padding for a cookie, allocate space (using alloc) for 128 // the array preceded by the specified padding, initialize the cookie if 129 // the padding is non-zero, and call the given constructor on each element. 130 // Return the address of the array proper, after the padding. 131 // 132 // If alloc throws an exception, rethrow the exception. If alloc returns 133 // NULL, return NULL. If the constructor throws an exception, call 134 // destructor for any already constructed elements, and rethrow the 135 // exception. If the destructor throws an exception, call std::terminate. 136 // 137 // The constructor may be NULL, in which case it must not be called. If the 138 // padding_size is zero, the destructor may be NULL; in that case it must 139 // not be called. 140 // 141 // Neither alloc nor dealloc may be NULL. 142 _LIBCXXABI_FUNC_VIS void * 143 __cxa_vec_new2(size_t element_count, size_t element_size, size_t padding_size, 144 void (*constructor)(void *), void (*destructor)(void *), 145 void *(*alloc)(size_t), void (*dealloc)(void *)) { 146 const size_t heap_size = element_count * element_size + padding_size; 147 char * const heap_block = static_cast<char *> ( alloc ( heap_size )); 148 char *vec_base = heap_block; 149 150 if ( NULL != vec_base ) { 151 st_heap_block2 heap ( dealloc, heap_block ); 152 153 // put the padding before the array elements 154 if ( 0 != padding_size ) { 155 vec_base += padding_size; 156 __set_element_count ( vec_base, element_count ); 157 } 158 159 // Construct the elements 160 __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor ); 161 heap.release (); // We're good! 162 } 163 164 return vec_base; 165 } 166 167 168 // Same as __cxa_vec_new2 except that the deallocation function takes both 169 // the object address and its size. 170 _LIBCXXABI_FUNC_VIS void * 171 __cxa_vec_new3(size_t element_count, size_t element_size, size_t padding_size, 172 void (*constructor)(void *), void (*destructor)(void *), 173 void *(*alloc)(size_t), void (*dealloc)(void *, size_t)) { 174 const size_t heap_size = element_count * element_size + padding_size; 175 char * const heap_block = static_cast<char *> ( alloc ( heap_size )); 176 char *vec_base = heap_block; 177 178 if ( NULL != vec_base ) { 179 st_heap_block3 heap ( dealloc, heap_block, heap_size ); 180 181 // put the padding before the array elements 182 if ( 0 != padding_size ) { 183 vec_base += padding_size; 184 __set_element_count ( vec_base, element_count ); 185 } 186 187 // Construct the elements 188 __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor ); 189 heap.release (); // We're good! 190 } 191 192 return vec_base; 193 } 194 195 196 // Given the (data) addresses of a destination and a source array, an 197 // element count and an element size, call the given copy constructor to 198 // copy each element from the source array to the destination array. The 199 // copy constructor's arguments are the destination address and source 200 // address, respectively. If an exception occurs, call the given destructor 201 // (if non-NULL) on each copied element and rethrow. If the destructor 202 // throws an exception, call terminate(). The constructor and or destructor 203 // pointers may be NULL. If either is NULL, no action is taken when it 204 // would have been called. 205 206 _LIBCXXABI_FUNC_VIS void __cxa_vec_cctor(void *dest_array, void *src_array, 207 size_t element_count, 208 size_t element_size, 209 void (*constructor)(void *, void *), 210 void (*destructor)(void *)) { 211 if ( NULL != constructor ) { 212 size_t idx = 0; 213 char *src_ptr = static_cast<char *>(src_array); 214 char *dest_ptr = static_cast<char *>(dest_array); 215 st_cxa_cleanup cleanup ( dest_array, idx, element_size, destructor ); 216 217 for ( idx = 0; idx < element_count; 218 ++idx, src_ptr += element_size, dest_ptr += element_size ) 219 constructor ( dest_ptr, src_ptr ); 220 cleanup.release (); // We're good! 221 } 222 } 223 224 225 // Given the (data) address of an array, not including any cookie padding, 226 // and the number and size of its elements, call the given constructor on 227 // each element. If the constructor throws an exception, call the given 228 // destructor for any already-constructed elements, and rethrow the 229 // exception. If the destructor throws an exception, call terminate(). The 230 // constructor and/or destructor pointers may be NULL. If either is NULL, 231 // no action is taken when it would have been called. 232 _LIBCXXABI_FUNC_VIS void 233 __cxa_vec_ctor(void *array_address, size_t element_count, size_t element_size, 234 void (*constructor)(void *), void (*destructor)(void *)) { 235 if ( NULL != constructor ) { 236 size_t idx; 237 char *ptr = static_cast <char *> ( array_address ); 238 st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor ); 239 240 // Construct the elements 241 for ( idx = 0; idx < element_count; ++idx, ptr += element_size ) 242 constructor ( ptr ); 243 cleanup.release (); // We're good! 244 } 245 } 246 247 // Given the (data) address of an array, the number of elements, and the 248 // size of its elements, call the given destructor on each element. If the 249 // destructor throws an exception, rethrow after destroying the remaining 250 // elements if possible. If the destructor throws a second exception, call 251 // terminate(). The destructor pointer may be NULL, in which case this 252 // routine does nothing. 253 _LIBCXXABI_FUNC_VIS void __cxa_vec_dtor(void *array_address, 254 size_t element_count, 255 size_t element_size, 256 void (*destructor)(void *)) { 257 if ( NULL != destructor ) { 258 char *ptr = static_cast <char *> (array_address); 259 size_t idx = element_count; 260 st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor ); 261 { 262 st_terminate exception_guard (__cxa_uncaught_exception ()); 263 ptr += element_count * element_size; // one past the last element 264 265 while ( idx-- > 0 ) { 266 ptr -= element_size; 267 destructor ( ptr ); 268 } 269 exception_guard.release (); // We're good ! 270 } 271 cleanup.release (); // We're still good! 272 } 273 } 274 275 // Given the (data) address of an array, the number of elements, and the 276 // size of its elements, call the given destructor on each element. If the 277 // destructor throws an exception, call terminate(). The destructor pointer 278 // may be NULL, in which case this routine does nothing. 279 _LIBCXXABI_FUNC_VIS void __cxa_vec_cleanup(void *array_address, 280 size_t element_count, 281 size_t element_size, 282 void (*destructor)(void *)) { 283 if ( NULL != destructor ) { 284 char *ptr = static_cast <char *> (array_address); 285 size_t idx = element_count; 286 st_terminate exception_guard; 287 288 ptr += element_count * element_size; // one past the last element 289 while ( idx-- > 0 ) { 290 ptr -= element_size; 291 destructor ( ptr ); 292 } 293 exception_guard.release (); // We're done! 294 } 295 } 296 297 298 // If the array_address is NULL, return immediately. Otherwise, given the 299 // (data) address of an array, the non-negative size of prefix padding for 300 // the cookie, and the size of its elements, call the given destructor on 301 // each element, using the cookie to determine the number of elements, and 302 // then delete the space by calling ::operator delete[](void *). If the 303 // destructor throws an exception, rethrow after (a) destroying the 304 // remaining elements, and (b) deallocating the storage. If the destructor 305 // throws a second exception, call terminate(). If padding_size is 0, the 306 // destructor pointer must be NULL. If the destructor pointer is NULL, no 307 // destructor call is to be made. 308 // 309 // The intent of this function is to permit an implementation to call this 310 // function when confronted with an expression of the form delete[] p in 311 // the source code, provided that the default deallocation function can be 312 // used. Therefore, the semantics of this function are consistent with 313 // those required by the standard. The requirement that the deallocation 314 // function be called even if the destructor throws an exception derives 315 // from the resolution to DR 353 to the C++ standard, which was adopted in 316 // April, 2003. 317 _LIBCXXABI_FUNC_VIS void __cxa_vec_delete(void *array_address, 318 size_t element_size, 319 size_t padding_size, 320 void (*destructor)(void *)) { 321 __cxa_vec_delete2 ( array_address, element_size, padding_size, 322 destructor, &::operator delete [] ); 323 } 324 325 // Same as __cxa_vec_delete, except that the given function is used for 326 // deallocation instead of the default delete function. If dealloc throws 327 // an exception, the result is undefined. The dealloc pointer may not be 328 // NULL. 329 _LIBCXXABI_FUNC_VIS void 330 __cxa_vec_delete2(void *array_address, size_t element_size, size_t padding_size, 331 void (*destructor)(void *), void (*dealloc)(void *)) { 332 if ( NULL != array_address ) { 333 char *vec_base = static_cast <char *> (array_address); 334 char *heap_block = vec_base - padding_size; 335 st_heap_block2 heap ( dealloc, heap_block ); 336 337 if ( 0 != padding_size && NULL != destructor ) // call the destructors 338 __cxa_vec_dtor ( array_address, __get_element_count ( vec_base ), 339 element_size, destructor ); 340 } 341 } 342 343 344 // Same as __cxa_vec_delete, except that the given function is used for 345 // deallocation instead of the default delete function. The deallocation 346 // function takes both the object address and its size. If dealloc throws 347 // an exception, the result is undefined. The dealloc pointer may not be 348 // NULL. 349 _LIBCXXABI_FUNC_VIS void 350 __cxa_vec_delete3(void *array_address, size_t element_size, size_t padding_size, 351 void (*destructor)(void *), void (*dealloc)(void *, size_t)) { 352 if ( NULL != array_address ) { 353 char *vec_base = static_cast <char *> (array_address); 354 char *heap_block = vec_base - padding_size; 355 const size_t element_count = padding_size ? __get_element_count ( vec_base ) : 0; 356 const size_t heap_block_size = element_size * element_count + padding_size; 357 st_heap_block3 heap ( dealloc, heap_block, heap_block_size ); 358 359 if ( 0 != padding_size && NULL != destructor ) // call the destructors 360 __cxa_vec_dtor ( array_address, element_count, element_size, destructor ); 361 } 362 } 363 364 365 } // extern "C" 366 367 } // abi 368
