1 //===------------------------ stdexcept.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 "stdexcept"
11 #include "new"
12 #include "string"
13 #include <cstdlib>
14 #include <cstring>
15 #include <cstdint>
16 #include <cstddef>
17 #include "system_error"
18 
19 // Use <cxxabi.h> to determine whether we're linking against libc++abi.
20 #if __has_include(<cxxabi.h>)
21 #include <cxxabi.h>
22 #endif
23 
24 // Note:  optimize for size
25 
26 #pragma GCC visibility push(hidden)
27 
28 namespace
29 {
30 
31 class __libcpp_nmstr
32 {
33 private:
34     const char* str_;
35 
36     typedef std::size_t unused_t;
37     typedef std::int32_t count_t;
38 
39     static const std::ptrdiff_t offset = static_cast<std::ptrdiff_t>(2*sizeof(unused_t) +
40                                                                        sizeof(count_t));
41 
42     count_t& count() const _NOEXCEPT {return (count_t&)(*(str_ - sizeof(count_t)));}
43 public:
44     explicit __libcpp_nmstr(const char* msg);
45     __libcpp_nmstr(const __libcpp_nmstr& s) _LIBCPP_CANTTHROW;
46     __libcpp_nmstr& operator=(const __libcpp_nmstr& s) _LIBCPP_CANTTHROW;
47     ~__libcpp_nmstr() _LIBCPP_CANTTHROW;
48     const char* c_str() const _NOEXCEPT {return str_;}
49 };
50 
51 __libcpp_nmstr::__libcpp_nmstr(const char* msg)
52 {
53     std::size_t len = strlen(msg);
54     str_ = new char[len + 1 + offset];
55     unused_t* c = (unused_t*)str_;
56     c[0] = c[1] = len;
57     str_ += offset;
58     count() = 0;
59     std::strcpy(const_cast<char*>(c_str()), msg);
60 }
61 
62 inline
63 __libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s)
64     : str_(s.str_)
65 {
66     __sync_add_and_fetch(&count(), 1);
67 }
68 
69 __libcpp_nmstr&
70 __libcpp_nmstr::operator=(const __libcpp_nmstr& s)
71 {
72     const char* p = str_;
73     str_ = s.str_;
74     __sync_add_and_fetch(&count(), 1);
75     if (__sync_add_and_fetch((count_t*)(p-sizeof(count_t)), -1) < 0)
76         delete [] (p-offset);
77     return *this;
78 }
79 
80 inline
81 __libcpp_nmstr::~__libcpp_nmstr()
82 {
83     if (__sync_add_and_fetch(&count(), -1) < 0)
84         delete [] (str_ - offset);
85 }
86 
87 }
88 
89 #pragma GCC visibility pop
90 
91 namespace std  // purposefully not using versioning namespace
92 {
93 
94 logic_error::logic_error(const string& msg)
95 {
96     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
97     ::new(&s) __libcpp_nmstr(msg.c_str());
98 }
99 
100 logic_error::logic_error(const char* msg)
101 {
102     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
103     ::new(&s) __libcpp_nmstr(msg);
104 }
105 
106 logic_error::logic_error(const logic_error& le) _NOEXCEPT
107 {
108     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
109     ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
110 }
111 
112 logic_error&
113 logic_error::operator=(const logic_error& le) _NOEXCEPT
114 {
115     __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
116     const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
117     s1 = s2;
118     return *this;
119 }
120 
121 #ifndef _LIBCPPABI_VERSION
122 
123 logic_error::~logic_error() _NOEXCEPT
124 {
125     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
126     s.~__libcpp_nmstr();
127 }
128 
129 const char*
130 logic_error::what() const _NOEXCEPT
131 {
132     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
133     return s.c_str();
134 }
135 
136 #endif
137 
138 runtime_error::runtime_error(const string& msg)
139 {
140     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
141     ::new(&s) __libcpp_nmstr(msg.c_str());
142 }
143 
144 runtime_error::runtime_error(const char* msg)
145 {
146     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
147     ::new(&s) __libcpp_nmstr(msg);
148 }
149 
150 runtime_error::runtime_error(const runtime_error& le) _NOEXCEPT
151 {
152     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
153     ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
154 }
155 
156 runtime_error&
157 runtime_error::operator=(const runtime_error& le) _NOEXCEPT
158 {
159     __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
160     const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
161     s1 = s2;
162     return *this;
163 }
164 
165 #ifndef _LIBCPPABI_VERSION
166 
167 runtime_error::~runtime_error() _NOEXCEPT
168 {
169     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
170     s.~__libcpp_nmstr();
171 }
172 
173 const char*
174 runtime_error::what() const _NOEXCEPT
175 {
176     __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
177     return s.c_str();
178 }
179 
180 domain_error::~domain_error() _NOEXCEPT {}
181 invalid_argument::~invalid_argument() _NOEXCEPT {}
182 length_error::~length_error() _NOEXCEPT {}
183 out_of_range::~out_of_range() _NOEXCEPT {}
184 
185 range_error::~range_error() _NOEXCEPT {}
186 overflow_error::~overflow_error() _NOEXCEPT {}
187 underflow_error::~underflow_error() _NOEXCEPT {}
188 
189 #endif
190 
191 }  // std
192