1// Copyright (c) 2009 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5// When possible, we implement allocator functions on top of the basic
6// low-level functions malloc() and free().  This way, including a new
7// allocator is as simple as providing just a small interface.
8//
9// As such, this file should not contain any allocator-specific code.
10
11// Implement a C++ style allocation, which always calls the new_handler
12// on failure.
13inline void* generic_cpp_alloc(size_t size, bool nothrow) {
14  void* ptr;
15  for (;;) {
16    ptr = malloc(size);
17    if (ptr)
18      return ptr;
19    if (!call_new_handler(nothrow))
20      break;
21  }
22  return ptr;
23}
24
25extern "C++" {
26
27void* __cdecl operator new(size_t size) {
28  return generic_cpp_alloc(size, false);
29}
30
31void operator delete(void* p) __THROW {
32  free(p);
33}
34
35void* operator new[](size_t size) {
36  return generic_cpp_alloc(size, false);
37}
38
39void operator delete[](void* p) __THROW {
40  free(p);
41}
42
43void* operator new(size_t size, const std::nothrow_t& nt) __THROW {
44  return generic_cpp_alloc(size, true);
45}
46
47void* operator new[](size_t size, const std::nothrow_t& nt) __THROW {
48  return generic_cpp_alloc(size, true);
49}
50
51// This function behaves similarly to MSVC's _set_new_mode.
52// If flag is 0 (default), calls to malloc will behave normally.
53// If flag is 1, calls to malloc will behave like calls to new,
54// and the std_new_handler will be invoked on failure.
55// Returns the previous mode.
56int _set_new_mode(int flag) __THROW {
57  int old_mode = new_mode;
58  new_mode = flag;
59  return old_mode;
60}
61
62}  // extern "C++"
63
64extern "C" {
65
66void* calloc(size_t n, size_t elem_size) __THROW {
67  // Overflow check
68  const size_t size = n * elem_size;
69  if (elem_size != 0 && size / elem_size != n) return NULL;
70
71  void* result = malloc(size);
72  if (result != NULL) {
73    memset(result, 0, size);
74  }
75  return result;
76}
77
78void cfree(void* p) __THROW {
79  free(p);
80}
81
82#ifdef WIN32
83
84void* _recalloc(void* p, size_t n, size_t elem_size) {
85  if (!p)
86    return calloc(n, elem_size);
87
88  // This API is a bit odd.
89  // Note: recalloc only guarantees zeroed memory when p is NULL.
90  //   Generally, calls to malloc() have padding.  So a request
91  //   to malloc N bytes actually malloc's N+x bytes.  Later, if
92  //   that buffer is passed to recalloc, we don't know what N
93  //   was anymore.  We only know what N+x is.  As such, there is
94  //   no way to know what to zero out.
95  const size_t size = n * elem_size;
96  if (elem_size != 0 && size / elem_size != n) return NULL;
97  return realloc(p, size);
98}
99
100void* _calloc_impl(size_t n, size_t size) {
101  return calloc(n, size);
102}
103
104#ifndef NDEBUG
105#undef malloc
106#undef free
107#undef calloc
108
109static int error_handler(int reportType) {
110  switch (reportType) {
111    case 0:  // _CRT_WARN
112      __debugbreak();
113      return 0;
114
115    case 1:  // _CRT_ERROR
116      __debugbreak();
117      return 0;
118
119    case 2:  // _CRT_ASSERT
120      __debugbreak();
121      return 0;
122  }
123  char* p = NULL;
124  *p = '\0';
125  return 0;
126}
127
128int _CrtDbgReport(int reportType,
129                  const char*,
130                  int, const char*,
131                  const char*,
132                  ...) {
133  return error_handler(reportType);
134}
135
136int _CrtDbgReportW(int reportType,
137                   const wchar_t*,
138                   int, const wchar_t*,
139                   const wchar_t*,
140                   ...) {
141  return error_handler(reportType);
142}
143
144int _CrtSetReportMode(int, int) {
145  return 0;
146}
147
148void* _malloc_dbg(size_t size, int , const char*, int) {
149  return malloc(size);
150}
151
152void* _realloc_dbg(void* ptr, size_t size, int, const char*, int) {
153  return realloc(ptr, size);
154}
155
156void _free_dbg(void* ptr, int) {
157  free(ptr);
158}
159
160void* _calloc_dbg(size_t n, size_t size, int, const char*, int) {
161  return calloc(n, size);
162}
163#endif  // NDEBUG
164
165#endif  // WIN32
166
167}  // extern C
168
169