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[])
__cxa_vec_new(size_t element_count,size_t element_size,size_t padding_size,void (* constructor)(void *),void (* destructor)(void *))117 void* __cxa_vec_new(
118 size_t element_count, size_t element_size, size_t padding_size,
119 void (*constructor)(void*), void (*destructor)(void*) ) {
120
121 return __cxa_vec_new2 ( element_count, element_size, padding_size,
122 constructor, destructor, &::operator new [], &::operator delete [] );
123 }
124
125
126
127 // Given the number and size of elements for an array and the non-negative
128 // size of prefix padding for a cookie, allocate space (using alloc) for
129 // the array preceded by the specified padding, initialize the cookie if
130 // the padding is non-zero, and call the given constructor on each element.
131 // Return the address of the array proper, after the padding.
132 //
133 // If alloc throws an exception, rethrow the exception. If alloc returns
134 // NULL, return NULL. If the constructor throws an exception, call
135 // destructor for any already constructed elements, and rethrow the
136 // exception. If the destructor throws an exception, call std::terminate.
137 //
138 // The constructor may be NULL, in which case it must not be called. If the
139 // padding_size is zero, the destructor may be NULL; in that case it must
140 // not be called.
141 //
142 // Neither alloc nor dealloc may be NULL.
__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 void* __cxa_vec_new2(
144 size_t element_count, size_t element_size, size_t padding_size,
145 void (*constructor)(void*), void (*destructor)(void*),
146 void* (*alloc)(size_t), void (*dealloc)(void*) ) {
147
148 const size_t heap_size = element_count * element_size + padding_size;
149 char * const heap_block = static_cast<char *> ( alloc ( heap_size ));
150 char *vec_base = heap_block;
151
152 if ( NULL != vec_base ) {
153 st_heap_block2 heap ( dealloc, heap_block );
154
155 // put the padding before the array elements
156 if ( 0 != padding_size ) {
157 vec_base += padding_size;
158 __set_element_count ( vec_base, element_count );
159 }
160
161 // Construct the elements
162 __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor );
163 heap.release (); // We're good!
164 }
165
166 return vec_base;
167 }
168
169
170 // Same as __cxa_vec_new2 except that the deallocation function takes both
171 // the object address and its size.
__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))172 void* __cxa_vec_new3(
173 size_t element_count, size_t element_size, size_t padding_size,
174 void (*constructor)(void*), void (*destructor)(void*),
175 void* (*alloc)(size_t), void (*dealloc)(void*, size_t) ) {
176
177 const size_t heap_size = element_count * element_size + padding_size;
178 char * const heap_block = static_cast<char *> ( alloc ( heap_size ));
179 char *vec_base = heap_block;
180
181 if ( NULL != vec_base ) {
182 st_heap_block3 heap ( dealloc, heap_block, heap_size );
183
184 // put the padding before the array elements
185 if ( 0 != padding_size ) {
186 vec_base += padding_size;
187 __set_element_count ( vec_base, element_count );
188 }
189
190 // Construct the elements
191 __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor );
192 heap.release (); // We're good!
193 }
194
195 return vec_base;
196 }
197
198
199 // Given the (data) addresses of a destination and a source array, an
200 // element count and an element size, call the given copy constructor to
201 // copy each element from the source array to the destination array. The
202 // copy constructor's arguments are the destination address and source
203 // address, respectively. If an exception occurs, call the given destructor
204 // (if non-NULL) on each copied element and rethrow. If the destructor
205 // throws an exception, call terminate(). The constructor and or destructor
206 // pointers may be NULL. If either is NULL, no action is taken when it
207 // would have been called.
208
__cxa_vec_cctor(void * dest_array,void * src_array,size_t element_count,size_t element_size,void (* constructor)(void *,void *),void (* destructor)(void *))209 void __cxa_vec_cctor( void* dest_array, void* src_array,
210 size_t element_count, size_t element_size,
211 void (*constructor) (void*, void*), void (*destructor)(void*) ) {
212
213 if ( NULL != constructor ) {
214 size_t idx = 0;
215 char *src_ptr = static_cast<char *>(src_array);
216 char *dest_ptr = static_cast<char *>(dest_array);
217 st_cxa_cleanup cleanup ( dest_array, idx, element_size, destructor );
218
219 for ( idx = 0; idx < element_count;
220 ++idx, src_ptr += element_size, dest_ptr += element_size )
221 constructor ( dest_ptr, src_ptr );
222 cleanup.release (); // We're good!
223 }
224 }
225
226
227 // Given the (data) address of an array, not including any cookie padding,
228 // and the number and size of its elements, call the given constructor on
229 // each element. If the constructor throws an exception, call the given
230 // destructor for any already-constructed elements, and rethrow the
231 // exception. If the destructor throws an exception, call terminate(). The
232 // constructor and/or destructor pointers may be NULL. If either is NULL,
233 // no action is taken when it would have been called.
__cxa_vec_ctor(void * array_address,size_t element_count,size_t element_size,void (* constructor)(void *),void (* destructor)(void *))234 void __cxa_vec_ctor(
235 void* array_address, size_t element_count, size_t element_size,
236 void (*constructor)(void*), void (*destructor)(void*) ) {
237
238 if ( NULL != constructor ) {
239 size_t idx;
240 char *ptr = static_cast <char *> ( array_address );
241 st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor );
242
243 // Construct the elements
244 for ( idx = 0; idx < element_count; ++idx, ptr += element_size )
245 constructor ( ptr );
246 cleanup.release (); // We're good!
247 }
248 }
249
250 // Given the (data) address of an array, the number of elements, and the
251 // size of its elements, call the given destructor on each element. If the
252 // destructor throws an exception, rethrow after destroying the remaining
253 // elements if possible. If the destructor throws a second exception, call
254 // terminate(). The destructor pointer may be NULL, in which case this
255 // routine does nothing.
__cxa_vec_dtor(void * array_address,size_t element_count,size_t element_size,void (* destructor)(void *))256 void __cxa_vec_dtor(
257 void* array_address, size_t element_count, size_t element_size,
258 void (*destructor)(void*) ) {
259
260 if ( NULL != destructor ) {
261 char *ptr = static_cast <char *> (array_address);
262 size_t idx = element_count;
263 st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor );
264 {
265 st_terminate exception_guard (__cxa_uncaught_exception ());
266 ptr += element_count * element_size; // one past the last element
267
268 while ( idx-- > 0 ) {
269 ptr -= element_size;
270 destructor ( ptr );
271 }
272 exception_guard.release (); // We're good !
273 }
274 cleanup.release (); // We're still good!
275 }
276 }
277
278 // Given the (data) address of an array, the number of elements, and the
279 // size of its elements, call the given destructor on each element. If the
280 // destructor throws an exception, call terminate(). The destructor pointer
281 // 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 *))282 void __cxa_vec_cleanup( void* array_address, size_t element_count,
283 size_t element_size, void (*destructor)(void*) ) {
284
285 if ( NULL != destructor ) {
286 char *ptr = static_cast <char *> (array_address);
287 size_t idx = element_count;
288 st_terminate exception_guard;
289
290 ptr += element_count * element_size; // one past the last element
291 while ( idx-- > 0 ) {
292 ptr -= element_size;
293 destructor ( ptr );
294 }
295 exception_guard.release (); // We're done!
296 }
297 }
298
299
300 // If the array_address is NULL, return immediately. Otherwise, given the
301 // (data) address of an array, the non-negative size of prefix padding for
302 // the cookie, and the size of its elements, call the given destructor on
303 // each element, using the cookie to determine the number of elements, and
304 // then delete the space by calling ::operator delete[](void *). If the
305 // destructor throws an exception, rethrow after (a) destroying the
306 // remaining elements, and (b) deallocating the storage. If the destructor
307 // throws a second exception, call terminate(). If padding_size is 0, the
308 // destructor pointer must be NULL. If the destructor pointer is NULL, no
309 // destructor call is to be made.
310 //
311 // The intent of this function is to permit an implementation to call this
312 // function when confronted with an expression of the form delete[] p in
313 // the source code, provided that the default deallocation function can be
314 // used. Therefore, the semantics of this function are consistent with
315 // those required by the standard. The requirement that the deallocation
316 // function be called even if the destructor throws an exception derives
317 // from the resolution to DR 353 to the C++ standard, which was adopted in
318 // April, 2003.
__cxa_vec_delete(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *))319 void __cxa_vec_delete( void* array_address,
320 size_t element_size, size_t padding_size, void (*destructor)(void*) ) {
321
322 __cxa_vec_delete2 ( array_address, element_size, padding_size,
323 destructor, &::operator delete [] );
324 }
325
326
327 // Same as __cxa_vec_delete, except that the given function is used for
328 // deallocation instead of the default delete function. If dealloc throws
329 // an exception, the result is undefined. The dealloc pointer may not be
330 // NULL.
__cxa_vec_delete2(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *),void (* dealloc)(void *))331 void __cxa_vec_delete2( void* array_address,
332 size_t element_size, size_t padding_size,
333 void (*destructor)(void*), void (*dealloc)(void*) ) {
334
335 if ( NULL != array_address ) {
336 char *vec_base = static_cast <char *> (array_address);
337 char *heap_block = vec_base - padding_size;
338 st_heap_block2 heap ( dealloc, heap_block );
339
340 if ( 0 != padding_size && NULL != destructor ) // call the destructors
341 __cxa_vec_dtor ( array_address, __get_element_count ( vec_base ),
342 element_size, destructor );
343 }
344 }
345
346
347 // Same as __cxa_vec_delete, except that the given function is used for
348 // deallocation instead of the default delete function. The deallocation
349 // function takes both the object address and its size. If dealloc throws
350 // an exception, the result is undefined. The dealloc pointer may not be
351 // NULL.
__cxa_vec_delete3(void * array_address,size_t element_size,size_t padding_size,void (* destructor)(void *),void (* dealloc)(void *,size_t))352 void __cxa_vec_delete3( void* array_address,
353 size_t element_size, size_t padding_size,
354 void (*destructor)(void*), void (*dealloc) (void*, size_t)) {
355
356 if ( NULL != array_address ) {
357 char *vec_base = static_cast <char *> (array_address);
358 char *heap_block = vec_base - padding_size;
359 const size_t element_count = padding_size ? __get_element_count ( vec_base ) : 0;
360 const size_t heap_block_size = element_size * element_count + padding_size;
361 st_heap_block3 heap ( dealloc, heap_block, heap_block_size );
362
363 if ( 0 != padding_size && NULL != destructor ) // call the destructors
364 __cxa_vec_dtor ( array_address, element_count, element_size, destructor );
365 }
366 }
367
368
369 } // extern "C"
370
371 } // abi
372