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
safe_malloc(size_t Sz)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
safe_calloc(size_t Count,size_t Sz)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
safe_realloc(void * Ptr,size_t Sz)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