xref: /freebsd/contrib/libcxxrt/memory.cc (revision bde84602722e3fad2e433e9b6bf6196909936481)
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 new_handler new_handl;
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 ATOMIC_SWAP(&new_handl, handler);
65 	}
66 	__attribute__((weak))
67 	new_handler get_new_handler(void)
68 	{
69 		return ATOMIC_LOAD(&new_handl);
70 	}
71 }
72 
73 
74 #if __cplusplus < 201103L
75 #define NOEXCEPT throw()
76 #define BADALLOC throw(std::bad_alloc)
77 #else
78 #define NOEXCEPT noexcept
79 #define BADALLOC
80 #endif
81 
82 namespace
83 {
84 	/**
85 	 * Helper for forwarding from no-throw operators to versions that can
86 	 * return nullptr.  Catches any exception and converts it into a nullptr
87 	 * return.
88 	 */
89 	template<void*(New)(size_t)>
90 	void *noexcept_new(size_t size)
91 	{
92 #if !defined(_CXXRT_NO_EXCEPTIONS)
93 	try
94 	{
95 		return New(size);
96 	} catch (...)
97 	{
98 		// nothrow operator new should return NULL in case of
99 		// std::bad_alloc exception in new handler
100 		return nullptr;
101 	}
102 #else
103 	return New(size);
104 #endif
105 	}
106 }
107 
108 
109 __attribute__((weak))
110 void* operator new(size_t size) BADALLOC
111 {
112 	if (0 == size)
113 	{
114 		size = 1;
115 	}
116 	void * mem = malloc(size);
117 	while (0 == mem)
118 	{
119 		new_handler h = std::get_new_handler();
120 		if (0 != h)
121 		{
122 			h();
123 		}
124 		else
125 		{
126 #if !defined(_CXXRT_NO_EXCEPTIONS)
127 			throw std::bad_alloc();
128 #else
129 			break;
130 #endif
131 		}
132 		mem = malloc(size);
133 	}
134 
135 	return mem;
136 }
137 
138 
139 __attribute__((weak))
140 void* operator new(size_t size, const std::nothrow_t &) NOEXCEPT
141 {
142 	return noexcept_new<(::operator new)>(size);
143 }
144 
145 
146 __attribute__((weak))
147 void operator delete(void * ptr) NOEXCEPT
148 {
149 	free(ptr);
150 }
151 
152 
153 __attribute__((weak))
154 void * operator new[](size_t size) BADALLOC
155 {
156 	return ::operator new(size);
157 }
158 
159 
160 __attribute__((weak))
161 void * operator new[](size_t size, const std::nothrow_t &) NOEXCEPT
162 {
163 	return noexcept_new<(::operator new[])>(size);
164 }
165 
166 
167 __attribute__((weak))
168 void operator delete[](void * ptr) NOEXCEPT
169 {
170 	::operator delete(ptr);
171 }
172 
173 // C++14 additional delete operators
174 
175 #if __cplusplus >= 201402L
176 
177 __attribute__((weak))
178 void operator delete(void * ptr, size_t) NOEXCEPT
179 {
180 	::operator delete(ptr);
181 }
182 
183 
184 __attribute__((weak))
185 void operator delete[](void * ptr, size_t) NOEXCEPT
186 {
187 	::operator delete(ptr);
188 }
189 
190 #endif
191