xref: /freebsd/contrib/libcxxrt/memory.cc (revision 56b17de1e8360fe131d425de20b5e75ff3ea897c)
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 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)>
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))
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))
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))
146 void operator delete(void * ptr) _LIBCXXRT_NOEXCEPT
147 {
148 	free(ptr);
149 }
150 
151 
152 __attribute__((weak))
153 void * operator new[](size_t size) BADALLOC
154 {
155 	return ::operator new(size);
156 }
157 
158 
159 __attribute__((weak))
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))
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))
177 void operator delete(void * ptr, size_t) _LIBCXXRT_NOEXCEPT
178 {
179 	::operator delete(ptr);
180 }
181 
182 
183 __attribute__((weak))
184 void operator delete[](void * ptr, size_t) _LIBCXXRT_NOEXCEPT
185 {
186 	::operator delete(ptr);
187 }
188 
189 #endif
190