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