xref: /llvm-project-15.0.7/libcxx/src/new.cpp (revision 0ab5e2cd)
1 //===--------------------------- new.cpp ----------------------------------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include <stdlib.h>
11 
12 #include "new"
13 
14 #if __APPLE__
15     #include <cxxabi.h>
16     // On Darwin, there are two STL shared libraries and a lower level ABI
17     // shared libray.  The global holding the current new handler is
18     // in the ABI library and named __cxa_new_handler.
19     #define __new_handler __cxxabiapple::__cxa_new_handler
20 #else  // __APPLE__
21     static std::new_handler __new_handler;
22 #endif
23 
24 // Implement all new and delete operators as weak definitions
25 // in this shared library, so that they can be overriden by programs
26 // that define non-weak copies of the functions.
27 
28 __attribute__((__weak__, __visibility__("default")))
29 void *
30 operator new(std::size_t size) throw (std::bad_alloc)
31 {
32     if (size == 0)
33         size = 1;
34     void* p;
35     while ((p = ::malloc(size)) == 0)
36     {
37         // If malloc fails and there is a new_handler,
38         // call it to try free up memory.
39         std::new_handler nh = std::get_new_handler();
40         if (nh)
41             nh();
42         else
43 #ifndef _LIBCPP_NO_EXCEPTIONS
44             throw std::bad_alloc();
45 #else
46             break;
47 #endif
48     }
49     return p;
50 }
51 
52 __attribute__((__weak__, __visibility__("default")))
53 void*
54 operator new(size_t size, const std::nothrow_t&) throw()
55 {
56     void* p = 0;
57 #ifndef _LIBCPP_NO_EXCEPTIONS
58     try
59     {
60 #endif  // _LIBCPP_NO_EXCEPTIONS
61         p = ::operator new(size);
62 #ifndef _LIBCPP_NO_EXCEPTIONS
63     }
64     catch (...)
65     {
66     }
67 #endif  // _LIBCPP_NO_EXCEPTIONS
68     return p;
69 }
70 
71 __attribute__((__weak__, __visibility__("default")))
72 void*
73 operator new[](size_t size) throw (std::bad_alloc)
74 {
75     return ::operator new(size);
76 }
77 
78 __attribute__((__weak__, __visibility__("default")))
79 void*
80 operator new[](size_t size, const std::nothrow_t& nothrow) throw()
81 {
82     void* p = 0;
83 #ifndef _LIBCPP_NO_EXCEPTIONS
84     try
85     {
86 #endif  // _LIBCPP_NO_EXCEPTIONS
87         p = ::operator new[](size);
88 #ifndef _LIBCPP_NO_EXCEPTIONS
89     }
90     catch (...)
91     {
92     }
93 #endif  // _LIBCPP_NO_EXCEPTIONS
94     return p;
95 }
96 
97 __attribute__((__weak__, __visibility__("default")))
98 void
99 operator delete(void* ptr) throw ()
100 {
101     if (ptr)
102         ::free(ptr);
103 }
104 
105 __attribute__((__weak__, __visibility__("default")))
106 void
107 operator delete(void* ptr, const std::nothrow_t&) throw ()
108 {
109     ::operator delete(ptr);
110 }
111 
112 __attribute__((__weak__, __visibility__("default")))
113 void
114 operator delete[] (void* ptr) throw ()
115 {
116     ::operator delete (ptr);
117 }
118 
119 __attribute__((__weak__, __visibility__("default")))
120 void
121 operator delete[] (void* ptr, const std::nothrow_t&) throw ()
122 {
123     ::operator delete[](ptr);
124 }
125 
126 namespace std
127 {
128 
129 const nothrow_t nothrow = {};
130 
131 new_handler
132 set_new_handler(new_handler handler) throw()
133 {
134     return __sync_lock_test_and_set(&__new_handler, handler);
135 }
136 
137 new_handler
138 get_new_handler() throw()
139 {
140     return __sync_fetch_and_add(&__new_handler, (new_handler)0);
141 }
142 
143 bad_alloc::bad_alloc() throw()
144 {
145 }
146 
147 bad_alloc::~bad_alloc() throw()
148 {
149 }
150 
151 const char*
152 bad_alloc::what() const throw()
153 {
154     return "std::bad_alloc";
155 }
156 
157 bad_array_new_length::bad_array_new_length() throw()
158 {
159 }
160 
161 bad_array_new_length::~bad_array_new_length() throw()
162 {
163 }
164 
165 const char*
166 bad_array_new_length::what() const throw()
167 {
168     return "bad_array_new_length";
169 }
170 
171 void
172 __throw_bad_alloc()
173 {
174 #ifndef _LIBCPP_NO_EXCEPTIONS
175     throw bad_alloc();
176 #endif
177 }
178 
179 }  // std
180