1 //===- MemAlloc.h - Memory allocation functions -----------------*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 /// \file 9 /// 10 /// This file defines counterparts of C library allocation functions defined in 11 /// the namespace 'std'. The new allocation functions crash on allocation 12 /// failure instead of returning null pointer. 13 /// 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_SUPPORT_MEMALLOC_H 17 #define LLVM_SUPPORT_MEMALLOC_H 18 19 #include "llvm/Support/Compiler.h" 20 #include "llvm/Support/ErrorHandling.h" 21 #include <cstdlib> 22 23 namespace llvm { 24 25 LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_malloc(size_t Sz) { 26 void *Result = std::malloc(Sz); 27 if (Result == nullptr) { 28 // It is implementation-defined whether allocation occurs if the space 29 // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting 30 // non-zero, if the space requested was zero. 31 if (Sz == 0) 32 return safe_malloc(1); 33 report_bad_alloc_error("Allocation failed"); 34 } 35 return Result; 36 } 37 38 LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_calloc(size_t Count, 39 size_t Sz) { 40 void *Result = std::calloc(Count, Sz); 41 if (Result == nullptr) { 42 // It is implementation-defined whether allocation occurs if the space 43 // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting 44 // non-zero, if the space requested was zero. 45 if (Count == 0 || Sz == 0) 46 return safe_malloc(1); 47 report_bad_alloc_error("Allocation failed"); 48 } 49 return Result; 50 } 51 52 LLVM_ATTRIBUTE_RETURNS_NONNULL inline void *safe_realloc(void *Ptr, size_t Sz) { 53 void *Result = std::realloc(Ptr, Sz); 54 if (Result == nullptr) { 55 // It is implementation-defined whether allocation occurs if the space 56 // requested is zero (ISO/IEC 9899:2018 7.22.3). Retry, requesting 57 // non-zero, if the space requested was zero. 58 if (Sz == 0) 59 return safe_malloc(1); 60 report_bad_alloc_error("Allocation failed"); 61 } 62 return Result; 63 } 64 65 /// Allocate a buffer of memory with the given size and alignment. 66 /// 67 /// When the compiler supports aligned operator new, this will use it to to 68 /// handle even over-aligned allocations. 69 /// 70 /// However, this doesn't make any attempt to leverage the fancier techniques 71 /// like posix_memalign due to portability. It is mostly intended to allow 72 /// compatibility with platforms that, after aligned allocation was added, use 73 /// reduced default alignment. 74 LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void * 75 allocate_buffer(size_t Size, size_t Alignment); 76 77 /// Deallocate a buffer of memory with the given size and alignment. 78 /// 79 /// If supported, this will used the sized delete operator. Also if supported, 80 /// this will pass the alignment to the delete operator. 81 /// 82 /// The pointer must have been allocated with the corresponding new operator, 83 /// most likely using the above helper. 84 void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment); 85 86 } // namespace llvm 87 #endif 88