1 /*
2 * Copyright 2010-2011 PathScale, Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are met:
6 *
7 * 1. Redistributions of source code must retain the above copyright notice,
8 * this list of conditions and the following disclaimer.
9 *
10 * 2. Redistributions in binary form must reproduce the above copyright notice,
11 * this list of conditions and the following disclaimer in the documentation
12 * and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS
15 * IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
16 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
21 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
23 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
24 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /**
28 * memory.cc - Contains stub definition of C++ new/delete operators.
29 *
30 * These definitions are intended to be used for testing and are weak symbols
31 * to allow them to be replaced by definitions from a STL implementation.
32 * These versions simply wrap malloc() and free(), they do not provide a
33 * C++-specific allocator.
34 */
35
36 #include <stddef.h>
37 #include <stdlib.h>
38 #include "stdexcept.h"
39 #include "atomic.h"
40
41
42 namespace std
43 {
44 struct nothrow_t {};
45 }
46
47
48 /// The type of the function called when allocation fails.
49 typedef void (*new_handler)();
50 /**
51 * The function to call when allocation fails. By default, there is no
52 * handler and a bad allocation exception is thrown if an allocation fails.
53 */
54 static atomic<new_handler> new_handl{nullptr};
55
56 namespace std
57 {
58 /**
59 * Sets a function to be called when there is a failure in new.
60 */
61 __attribute__((weak))
set_new_handler(new_handler handler)62 new_handler set_new_handler(new_handler handler)
63 {
64 return new_handl.exchange(handler);
65 }
66
67 __attribute__((weak))
get_new_handler(void)68 new_handler get_new_handler(void)
69 {
70 return new_handl.load();
71 }
72 }
73
74
75 #if __cplusplus < 201103L
76 #define BADALLOC throw(std::bad_alloc)
77 #else
78 #define BADALLOC
79 #endif
80
81 namespace
82 {
83 /**
84 * Helper for forwarding from no-throw operators to versions that can
85 * return nullptr. Catches any exception and converts it into a nullptr
86 * return.
87 */
88 template<void*(New)(size_t)>
noexcept_new(size_t size)89 void *noexcept_new(size_t size)
90 {
91 #if !defined(_CXXRT_NO_EXCEPTIONS)
92 try
93 {
94 return New(size);
95 } catch (...)
96 {
97 // nothrow operator new should return NULL in case of
98 // std::bad_alloc exception in new handler
99 return nullptr;
100 }
101 #else
102 return New(size);
103 #endif
104 }
105 }
106
107
108 __attribute__((weak))
operator new(size_t size)109 void* operator new(size_t size) BADALLOC
110 {
111 if (0 == size)
112 {
113 size = 1;
114 }
115 void * mem = malloc(size);
116 while (0 == mem)
117 {
118 new_handler h = std::get_new_handler();
119 if (0 != h)
120 {
121 h();
122 }
123 else
124 {
125 #if !defined(_CXXRT_NO_EXCEPTIONS)
126 throw std::bad_alloc();
127 #else
128 break;
129 #endif
130 }
131 mem = malloc(size);
132 }
133
134 return mem;
135 }
136
137
138 __attribute__((weak))
operator new(size_t size,const std::nothrow_t &)139 void* operator new(size_t size, const std::nothrow_t &) _LIBCXXRT_NOEXCEPT
140 {
141 return noexcept_new<(::operator new)>(size);
142 }
143
144
145 __attribute__((weak))
operator delete(void * ptr)146 void operator delete(void * ptr) _LIBCXXRT_NOEXCEPT
147 {
148 free(ptr);
149 }
150
151
152 __attribute__((weak))
operator new[](size_t size)153 void * operator new[](size_t size) BADALLOC
154 {
155 return ::operator new(size);
156 }
157
158
159 __attribute__((weak))
operator new[](size_t size,const std::nothrow_t &)160 void * operator new[](size_t size, const std::nothrow_t &) _LIBCXXRT_NOEXCEPT
161 {
162 return noexcept_new<(::operator new[])>(size);
163 }
164
165
166 __attribute__((weak))
operator delete[](void * ptr)167 void operator delete[](void * ptr) _LIBCXXRT_NOEXCEPT
168 {
169 ::operator delete(ptr);
170 }
171
172 // C++14 additional delete operators
173
174 #if __cplusplus >= 201402L
175
176 __attribute__((weak))
operator delete(void * ptr,size_t)177 void operator delete(void * ptr, size_t) _LIBCXXRT_NOEXCEPT
178 {
179 ::operator delete(ptr);
180 }
181
182
183 __attribute__((weak))
operator delete[](void * ptr,size_t)184 void operator delete[](void * ptr, size_t) _LIBCXXRT_NOEXCEPT
185 {
186 ::operator delete(ptr);
187 }
188
189 #endif
190