| //===----------------------------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| // |
| // This file implements the "Array Construction and Destruction APIs" |
| // https://itanium-cxx-abi.github.io/cxx-abi/abi.html#array-ctor |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "cxxabi.h" |
| #include "__cxxabi_config.h" |
| |
| #include <exception> // for std::terminate |
| #include <new> // for std::bad_array_new_length |
| |
| #include "abort_message.h" |
| |
| #ifndef __has_builtin |
| #define __has_builtin(x) 0 |
| #endif |
| |
| namespace __cxxabiv1 { |
| |
| // |
| // Helper routines and classes |
| // |
| |
| namespace { |
| inline static size_t __get_element_count ( void *p ) { |
| return static_cast <size_t *> (p)[-1]; |
| } |
| |
| inline static void __set_element_count ( void *p, size_t element_count ) { |
| static_cast <size_t *> (p)[-1] = element_count; |
| } |
| |
| |
| // A pair of classes to simplify exception handling and control flow. |
| // They get passed a block of memory in the constructor, and unless the |
| // 'release' method is called, they deallocate the memory in the destructor. |
| // Preferred usage is to allocate some memory, attach it to one of these objects, |
| // and then, when all the operations to set up the memory block have succeeded, |
| // call 'release'. If any of the setup operations fail, or an exception is |
| // thrown, then the block is automatically deallocated. |
| // |
| // The only difference between these two classes is the signature for the |
| // deallocation function (to match new2/new3 and delete2/delete3. |
| class st_heap_block2 { |
| public: |
| typedef void (*dealloc_f)(void *); |
| |
| st_heap_block2 ( dealloc_f dealloc, void *ptr ) |
| : dealloc_ ( dealloc ), ptr_ ( ptr ), enabled_ ( true ) {} |
| ~st_heap_block2 () { if ( enabled_ ) dealloc_ ( ptr_ ) ; } |
| void release () { enabled_ = false; } |
| |
| private: |
| dealloc_f dealloc_; |
| void *ptr_; |
| bool enabled_; |
| }; |
| |
| class st_heap_block3 { |
| public: |
| typedef void (*dealloc_f)(void *, size_t); |
| |
| st_heap_block3 ( dealloc_f dealloc, void *ptr, size_t size ) |
| : dealloc_ ( dealloc ), ptr_ ( ptr ), size_ ( size ), enabled_ ( true ) {} |
| ~st_heap_block3 () { if ( enabled_ ) dealloc_ ( ptr_, size_ ) ; } |
| void release () { enabled_ = false; } |
| |
| private: |
| dealloc_f dealloc_; |
| void *ptr_; |
| size_t size_; |
| bool enabled_; |
| }; |
| |
| class st_cxa_cleanup { |
| public: |
| typedef void (*destruct_f)(void *); |
| |
| st_cxa_cleanup ( void *ptr, size_t &idx, size_t element_size, destruct_f destructor ) |
| : ptr_ ( ptr ), idx_ ( idx ), element_size_ ( element_size ), |
| destructor_ ( destructor ), enabled_ ( true ) {} |
| ~st_cxa_cleanup () { |
| if ( enabled_ ) |
| __cxa_vec_cleanup ( ptr_, idx_, element_size_, destructor_ ); |
| } |
| |
| void release () { enabled_ = false; } |
| |
| private: |
| void *ptr_; |
| size_t &idx_; |
| size_t element_size_; |
| destruct_f destructor_; |
| bool enabled_; |
| }; |
| |
| class st_terminate { |
| public: |
| st_terminate ( bool enabled = true ) : enabled_ ( enabled ) {} |
| ~st_terminate () { if ( enabled_ ) std::terminate (); } |
| void release () { enabled_ = false; } |
| private: |
| bool enabled_ ; |
| }; |
| } |
| |
| // |
| // Externally visible routines |
| // |
| |
| namespace { |
| _LIBCXXABI_NORETURN |
| void throw_bad_array_new_length() { |
| #ifndef _LIBCXXABI_NO_EXCEPTIONS |
| throw std::bad_array_new_length(); |
| #else |
| abort_message("__cxa_vec_new failed to allocate memory"); |
| #endif |
| } |
| |
| bool mul_overflow(size_t x, size_t y, size_t *res) { |
| #if (defined(_LIBCXXABI_COMPILER_CLANG) && __has_builtin(__builtin_mul_overflow)) \ |
| || defined(_LIBCXXABI_COMPILER_GCC) |
| return __builtin_mul_overflow(x, y, res); |
| #else |
| *res = x * y; |
| return x && ((*res / x) != y); |
| #endif |
| } |
| |
| bool add_overflow(size_t x, size_t y, size_t *res) { |
| #if (defined(_LIBCXXABI_COMPILER_CLANG) && __has_builtin(__builtin_add_overflow)) \ |
| || defined(_LIBCXXABI_COMPILER_GCC) |
| return __builtin_add_overflow(x, y, res); |
| #else |
| *res = x + y; |
| return *res < y; |
| #endif |
| } |
| |
| size_t calculate_allocation_size_or_throw(size_t element_count, |
| size_t element_size, |
| size_t padding_size) { |
| size_t element_heap_size; |
| if (mul_overflow(element_count, element_size, &element_heap_size)) |
| throw_bad_array_new_length(); |
| |
| size_t allocation_size; |
| if (add_overflow(element_heap_size, padding_size, &allocation_size)) |
| throw_bad_array_new_length(); |
| |
| return allocation_size; |
| } |
| |
| } // namespace |
| |
| extern "C" { |
| |
| // Equivalent to |
| // |
| // __cxa_vec_new2(element_count, element_size, padding_size, constructor, |
| // destructor, &::operator new[], &::operator delete[]) |
| _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 *)) { |
| return __cxa_vec_new2 ( element_count, element_size, padding_size, |
| constructor, destructor, &::operator new [], &::operator delete [] ); |
| } |
| |
| |
| // Given the number and size of elements for an array and the non-negative |
| // size of prefix padding for a cookie, allocate space (using alloc) for |
| // the array preceded by the specified padding, initialize the cookie if |
| // the padding is non-zero, and call the given constructor on each element. |
| // Return the address of the array proper, after the padding. |
| // |
| // If alloc throws an exception, rethrow the exception. If alloc returns |
| // NULL, return NULL. If the constructor throws an exception, call |
| // destructor for any already constructed elements, and rethrow the |
| // exception. If the destructor throws an exception, call std::terminate. |
| // |
| // The constructor may be NULL, in which case it must not be called. If the |
| // padding_size is zero, the destructor may be NULL; in that case it must |
| // not be called. |
| // |
| // Neither alloc nor dealloc may be NULL. |
| _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 *)) { |
| const size_t heap_size = calculate_allocation_size_or_throw( |
| element_count, element_size, padding_size); |
| char* const heap_block = static_cast<char*>(alloc(heap_size)); |
| char* vec_base = heap_block; |
| |
| if (NULL != vec_base) { |
| st_heap_block2 heap(dealloc, heap_block); |
| |
| // put the padding before the array elements |
| if ( 0 != padding_size ) { |
| vec_base += padding_size; |
| __set_element_count ( vec_base, element_count ); |
| } |
| |
| // Construct the elements |
| __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor ); |
| heap.release (); // We're good! |
| } |
| |
| return vec_base; |
| } |
| |
| |
| // Same as __cxa_vec_new2 except that the deallocation function takes both |
| // the object address and its size. |
| _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)) { |
| const size_t heap_size = calculate_allocation_size_or_throw( |
| element_count, element_size, padding_size); |
| char* const heap_block = static_cast<char*>(alloc(heap_size)); |
| char* vec_base = heap_block; |
| |
| if (NULL != vec_base) { |
| st_heap_block3 heap(dealloc, heap_block, heap_size); |
| |
| // put the padding before the array elements |
| if ( 0 != padding_size ) { |
| vec_base += padding_size; |
| __set_element_count ( vec_base, element_count ); |
| } |
| |
| // Construct the elements |
| __cxa_vec_ctor ( vec_base, element_count, element_size, constructor, destructor ); |
| heap.release (); // We're good! |
| } |
| |
| return vec_base; |
| } |
| |
| |
| // Given the (data) addresses of a destination and a source array, an |
| // element count and an element size, call the given copy constructor to |
| // copy each element from the source array to the destination array. The |
| // copy constructor's arguments are the destination address and source |
| // address, respectively. If an exception occurs, call the given destructor |
| // (if non-NULL) on each copied element and rethrow. If the destructor |
| // throws an exception, call terminate(). The constructor and or destructor |
| // pointers may be NULL. If either is NULL, no action is taken when it |
| // would have been called. |
| |
| _LIBCXXABI_FUNC_VIS void __cxa_vec_cctor(void *dest_array, void *src_array, |
| size_t element_count, |
| size_t element_size, |
| void (*constructor)(void *, void *), |
| void (*destructor)(void *)) { |
| if ( NULL != constructor ) { |
| size_t idx = 0; |
| char *src_ptr = static_cast<char *>(src_array); |
| char *dest_ptr = static_cast<char *>(dest_array); |
| st_cxa_cleanup cleanup ( dest_array, idx, element_size, destructor ); |
| |
| for ( idx = 0; idx < element_count; |
| ++idx, src_ptr += element_size, dest_ptr += element_size ) |
| constructor ( dest_ptr, src_ptr ); |
| cleanup.release (); // We're good! |
| } |
| } |
| |
| |
| // Given the (data) address of an array, not including any cookie padding, |
| // and the number and size of its elements, call the given constructor on |
| // each element. If the constructor throws an exception, call the given |
| // destructor for any already-constructed elements, and rethrow the |
| // exception. If the destructor throws an exception, call terminate(). The |
| // constructor and/or destructor pointers may be NULL. If either is NULL, |
| // no action is taken when it would have been called. |
| _LIBCXXABI_FUNC_VIS void |
| __cxa_vec_ctor(void *array_address, size_t element_count, size_t element_size, |
| void (*constructor)(void *), void (*destructor)(void *)) { |
| if ( NULL != constructor ) { |
| size_t idx; |
| char *ptr = static_cast <char *> ( array_address ); |
| st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor ); |
| |
| // Construct the elements |
| for ( idx = 0; idx < element_count; ++idx, ptr += element_size ) |
| constructor ( ptr ); |
| cleanup.release (); // We're good! |
| } |
| } |
| |
| // Given the (data) address of an array, the number of elements, and the |
| // size of its elements, call the given destructor on each element. If the |
| // destructor throws an exception, rethrow after destroying the remaining |
| // elements if possible. If the destructor throws a second exception, call |
| // terminate(). The destructor pointer may be NULL, in which case this |
| // routine does nothing. |
| _LIBCXXABI_FUNC_VIS void __cxa_vec_dtor(void *array_address, |
| size_t element_count, |
| size_t element_size, |
| void (*destructor)(void *)) { |
| if ( NULL != destructor ) { |
| char *ptr = static_cast <char *> (array_address); |
| size_t idx = element_count; |
| st_cxa_cleanup cleanup ( array_address, idx, element_size, destructor ); |
| { |
| st_terminate exception_guard (__cxa_uncaught_exception ()); |
| ptr += element_count * element_size; // one past the last element |
| |
| while ( idx-- > 0 ) { |
| ptr -= element_size; |
| destructor ( ptr ); |
| } |
| exception_guard.release (); // We're good ! |
| } |
| cleanup.release (); // We're still good! |
| } |
| } |
| |
| // Given the (data) address of an array, the number of elements, and the |
| // size of its elements, call the given destructor on each element. If the |
| // destructor throws an exception, call terminate(). The destructor pointer |
| // may be NULL, in which case this routine does nothing. |
| _LIBCXXABI_FUNC_VIS void __cxa_vec_cleanup(void *array_address, |
| size_t element_count, |
| size_t element_size, |
| void (*destructor)(void *)) { |
| if ( NULL != destructor ) { |
| char *ptr = static_cast <char *> (array_address); |
| size_t idx = element_count; |
| st_terminate exception_guard; |
| |
| ptr += element_count * element_size; // one past the last element |
| while ( idx-- > 0 ) { |
| ptr -= element_size; |
| destructor ( ptr ); |
| } |
| exception_guard.release (); // We're done! |
| } |
| } |
| |
| |
| // If the array_address is NULL, return immediately. Otherwise, given the |
| // (data) address of an array, the non-negative size of prefix padding for |
| // the cookie, and the size of its elements, call the given destructor on |
| // each element, using the cookie to determine the number of elements, and |
| // then delete the space by calling ::operator delete[](void *). If the |
| // destructor throws an exception, rethrow after (a) destroying the |
| // remaining elements, and (b) deallocating the storage. If the destructor |
| // throws a second exception, call terminate(). If padding_size is 0, the |
| // destructor pointer must be NULL. If the destructor pointer is NULL, no |
| // destructor call is to be made. |
| // |
| // The intent of this function is to permit an implementation to call this |
| // function when confronted with an expression of the form delete[] p in |
| // the source code, provided that the default deallocation function can be |
| // used. Therefore, the semantics of this function are consistent with |
| // those required by the standard. The requirement that the deallocation |
| // function be called even if the destructor throws an exception derives |
| // from the resolution to DR 353 to the C++ standard, which was adopted in |
| // April, 2003. |
| _LIBCXXABI_FUNC_VIS void __cxa_vec_delete(void *array_address, |
| size_t element_size, |
| size_t padding_size, |
| void (*destructor)(void *)) { |
| __cxa_vec_delete2 ( array_address, element_size, padding_size, |
| destructor, &::operator delete [] ); |
| } |
| |
| // Same as __cxa_vec_delete, except that the given function is used for |
| // deallocation instead of the default delete function. If dealloc throws |
| // an exception, the result is undefined. The dealloc pointer may not be |
| // NULL. |
| _LIBCXXABI_FUNC_VIS void |
| __cxa_vec_delete2(void *array_address, size_t element_size, size_t padding_size, |
| void (*destructor)(void *), void (*dealloc)(void *)) { |
| if ( NULL != array_address ) { |
| char *vec_base = static_cast <char *> (array_address); |
| char *heap_block = vec_base - padding_size; |
| st_heap_block2 heap ( dealloc, heap_block ); |
| |
| if ( 0 != padding_size && NULL != destructor ) // call the destructors |
| __cxa_vec_dtor ( array_address, __get_element_count ( vec_base ), |
| element_size, destructor ); |
| } |
| } |
| |
| |
| // Same as __cxa_vec_delete, except that the given function is used for |
| // deallocation instead of the default delete function. The deallocation |
| // function takes both the object address and its size. If dealloc throws |
| // an exception, the result is undefined. The dealloc pointer may not be |
| // NULL. |
| _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)) { |
| if ( NULL != array_address ) { |
| char *vec_base = static_cast <char *> (array_address); |
| char *heap_block = vec_base - padding_size; |
| const size_t element_count = padding_size ? __get_element_count ( vec_base ) : 0; |
| const size_t heap_block_size = element_size * element_count + padding_size; |
| st_heap_block3 heap ( dealloc, heap_block, heap_block_size ); |
| |
| if ( 0 != padding_size && NULL != destructor ) // call the destructors |
| __cxa_vec_dtor ( array_address, element_count, element_size, destructor ); |
| } |
| } |
| |
| |
| } // extern "C" |
| |
| } // abi |