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 {
__get_element_count(void * p)25 inline static size_t __get_element_count ( void *p ) {
26 return static_cast <size_t *> (p)[-1];
27 }
28
__set_element_count(void * p,size_t element_count)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
st_heap_block2(dealloc_f dealloc,void * ptr)48 st_heap_block2 ( dealloc_f dealloc, void *ptr )
49 : dealloc_ ( dealloc ), ptr_ ( ptr ), enabled_ ( true ) {}
~st_heap_block2()50 ~st_heap_block2 () { if ( enabled_ ) dealloc_ ( ptr_ ) ; }
release()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
st_heap_block3(dealloc_f dealloc,void * ptr,size_t size)63 st_heap_block3 ( dealloc_f dealloc, void *ptr, size_t size )
64 : dealloc_ ( dealloc ), ptr_ ( ptr ), size_ ( size ), enabled_ ( true ) {}
~st_heap_block3()65 ~st_heap_block3 () { if ( enabled_ ) dealloc_ ( ptr_, size_ ) ; }
release()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
st_cxa_cleanup(void * ptr,size_t & idx,size_t element_size,destruct_f destructor)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 ) {}
~st_cxa_cleanup()82 ~st_cxa_cleanup () {
83 if ( enabled_ )
84 __cxa_vec_cleanup ( ptr_, idx_, element_size_, destructor_ );
85 }
86
release()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:
st_terminate(bool enabled=true)99 st_terminate ( bool enabled = true ) : enabled_ ( enabled ) {}
~st_terminate()100 ~st_terminate () { if ( enabled_ ) std::terminate (); }
release()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 *
__cxa_vec_new(size_t element_count,size_t element_size,size_t padding_size,void (* constructor)(void *),void (* destructor)(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 *
__cxa_vec_new2(size_t element_count,size_t element_size,size_t padding_size,void (* constructor)(void *),void (* destructor)(void *),void * (* alloc)(size_t),void (* dealloc)(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 *
__cxa_vec_new3(size_t element_count,size_t element_size,size_t padding_size,void (* constructor)(void *),void (* destructor)(void *),void * (* alloc)(size_t),void (* dealloc)(void *,size_t))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
__cxa_vec_cctor(void * dest_array,void * src_array,size_t element_count,size_t element_size,void (* constructor)(void *,void *),void (* destructor)(void *))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
__cxa_vec_ctor(void * array_address,size_t element_count,size_t element_size,void (* constructor)(void *),void (* destructor)(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.
__cxa_vec_dtor(void * array_address,size_t element_count,size_t element_size,void (* destructor)(void *))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.
__cxa_vec_cleanup(void * array_address,size_t element_count,size_t element_size,void (* destructor)(void *))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.
__cxa_vec_delete(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *))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
__cxa_vec_delete2(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *),void (* dealloc)(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
__cxa_vec_delete3(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *),void (* dealloc)(void *,size_t))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