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(size: 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(Sz: 1); |
33 | report_bad_alloc_error(Reason: "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(nmemb: Count, size: 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(Sz: 1); |
47 | report_bad_alloc_error(Reason: "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: Ptr, size: 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(Sz: 1); |
60 | report_bad_alloc_error(Reason: "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 | |