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
23namespace llvm {
24
25LLVM_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
38LLVM_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
52LLVM_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.
74LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void *
75allocate_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.
84void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment);
85
86} // namespace llvm
87#endif
88