xref: /freebsd/contrib/libcxxrt/memory.cc (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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))
62 	new_handler set_new_handler(new_handler handler)
63 	{
64 		return new_handl.exchange(handler);
65 	}
66 
67 	__attribute__((weak))
68 	new_handler get_new_handler(void)
69 	{
70 		return new_handl.load();
71 	}
72 }
73 
74 
75 #if __cplusplus < 201103L
76 #define NOEXCEPT throw()
77 #define BADALLOC throw(std::bad_alloc)
78 #else
79 #define NOEXCEPT noexcept
80 #define BADALLOC
81 #endif
82 
83 namespace
84 {
85 	/**
86 	 * Helper for forwarding from no-throw operators to versions that can
87 	 * return nullptr.  Catches any exception and converts it into a nullptr
88 	 * return.
89 	 */
90 	template<void*(New)(size_t)>
91 	void *noexcept_new(size_t size)
92 	{
93 #if !defined(_CXXRT_NO_EXCEPTIONS)
94 	try
95 	{
96 		return New(size);
97 	} catch (...)
98 	{
99 		// nothrow operator new should return NULL in case of
100 		// std::bad_alloc exception in new handler
101 		return nullptr;
102 	}
103 #else
104 	return New(size);
105 #endif
106 	}
107 }
108 
109 
110 __attribute__((weak))
111 void* operator new(size_t size) BADALLOC
112 {
113 	if (0 == size)
114 	{
115 		size = 1;
116 	}
117 	void * mem = malloc(size);
118 	while (0 == mem)
119 	{
120 		new_handler h = std::get_new_handler();
121 		if (0 != h)
122 		{
123 			h();
124 		}
125 		else
126 		{
127 #if !defined(_CXXRT_NO_EXCEPTIONS)
128 			throw std::bad_alloc();
129 #else
130 			break;
131 #endif
132 		}
133 		mem = malloc(size);
134 	}
135 
136 	return mem;
137 }
138 
139 
140 __attribute__((weak))
141 void* operator new(size_t size, const std::nothrow_t &) NOEXCEPT
142 {
143 	return noexcept_new<(::operator new)>(size);
144 }
145 
146 
147 __attribute__((weak))
148 void operator delete(void * ptr) NOEXCEPT
149 {
150 	free(ptr);
151 }
152 
153 
154 __attribute__((weak))
155 void * operator new[](size_t size) BADALLOC
156 {
157 	return ::operator new(size);
158 }
159 
160 
161 __attribute__((weak))
162 void * operator new[](size_t size, const std::nothrow_t &) NOEXCEPT
163 {
164 	return noexcept_new<(::operator new[])>(size);
165 }
166 
167 
168 __attribute__((weak))
169 void operator delete[](void * ptr) NOEXCEPT
170 {
171 	::operator delete(ptr);
172 }
173 
174 // C++14 additional delete operators
175 
176 #if __cplusplus >= 201402L
177 
178 __attribute__((weak))
179 void operator delete(void * ptr, size_t) NOEXCEPT
180 {
181 	::operator delete(ptr);
182 }
183 
184 
185 __attribute__((weak))
186 void operator delete[](void * ptr, size_t) NOEXCEPT
187 {
188 	::operator delete(ptr);
189 }
190 
191 #endif
192