LLVM  14.0.0git
MemAlloc.h
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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"
21 #include <cstdlib>
22 
23 namespace llvm {
24 
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.
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
llvm::Check::Size
@ Size
Definition: FileCheck.h:73
LLVM_ATTRIBUTE_RETURNS_NOALIAS
#define LLVM_ATTRIBUTE_RETURNS_NOALIAS
\macro LLVM_ATTRIBUTE_RETURNS_NOALIAS Used to mark a function as returning a pointer that does not al...
Definition: Compiler.h:260
llvm
---------------------— PointerInfo ------------------------------------—
Definition: AllocatorList.h:23
ErrorHandling.h
llvm::allocate_buffer
LLVM_ATTRIBUTE_RETURNS_NONNULL LLVM_ATTRIBUTE_RETURNS_NOALIAS void * allocate_buffer(size_t Size, size_t Alignment)
Allocate a buffer of memory with the given size and alignment.
Definition: MemAlloc.cpp:14
llvm::safe_calloc
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_calloc(size_t Count, size_t Sz)
Definition: MemAlloc.h:38
llvm::deallocate_buffer
void deallocate_buffer(void *Ptr, size_t Size, size_t Alignment)
Deallocate a buffer of memory with the given size and alignment.
Definition: MemAlloc.cpp:23
llvm::report_bad_alloc_error
void report_bad_alloc_error(const char *Reason, bool GenCrashDiag=true)
Reports a bad alloc error, calling any user defined bad alloc error handler.
Definition: ErrorHandling.cpp:147
LLVM_ATTRIBUTE_RETURNS_NONNULL
#define LLVM_ATTRIBUTE_RETURNS_NONNULL
Definition: Compiler.h:250
Compiler.h
llvm::safe_realloc
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_realloc(void *Ptr, size_t Sz)
Definition: MemAlloc.h:52
llvm::safe_malloc
LLVM_ATTRIBUTE_RETURNS_NONNULL void * safe_malloc(size_t Sz)
Definition: MemAlloc.h:25