Mercurial > hg > CbC > CbC_llvm
diff libcxxabi/src/cxa_vector.cpp @ 150:1d019706d866
LLVM10
author | anatofuz |
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date | Thu, 13 Feb 2020 15:10:13 +0900 |
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children | 0572611fdcc8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/libcxxabi/src/cxa_vector.cpp Thu Feb 13 15:10:13 2020 +0900 @@ -0,0 +1,421 @@ +//===-------------------------- cxa_vector.cpp ---------------------------===// +// +// 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 { + +#if 0 +#pragma mark --Helper routines and classes -- +#endif + +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_ ; + }; +} + +#if 0 +#pragma mark --Externally visible routines-- +#endif + +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