stdexcept.cpp revision 262801 
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#ifndef __has_include
20#define __has_include(inc) 0
21#endif
22
23#ifdef __APPLE__
24#include <cxxabi.h>
25#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
26#include <cxxabi.h>
27#endif
28
29// Note:  optimize for size
30
31#if ! defined(_LIBCPP_MSVC)
32#pragma GCC visibility push(hidden)
33#endif
34
35namespace
36{
37
38class __libcpp_nmstr
39{
40private:
41    const char* str_;
42
43    typedef std::size_t unused_t;
44    typedef std::ptrdiff_t count_t;
45
46    static const std::ptrdiff_t offset = static_cast<std::ptrdiff_t>(2*sizeof(unused_t) +
47                                                                       sizeof(count_t));
48
49    count_t& count() const _NOEXCEPT {return (count_t&)(*(str_ - sizeof(count_t)));}
50public:
51    explicit __libcpp_nmstr(const char* msg);
52    __libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT;
53    __libcpp_nmstr& operator=(const __libcpp_nmstr& s) _NOEXCEPT;
54    ~__libcpp_nmstr();
55    const char* c_str() const _NOEXCEPT {return str_;}
56};
57
58__libcpp_nmstr::__libcpp_nmstr(const char* msg)
59{
60    std::size_t len = strlen(msg);
61    str_ = new char[len + 1 + offset];
62    unused_t* c = (unused_t*)str_;
63    c[0] = c[1] = len;
64    str_ += offset;
65    count() = 0;
66    std::memcpy(const_cast<char*>(c_str()), msg, len + 1);
67}
68
69inline
70__libcpp_nmstr::__libcpp_nmstr(const __libcpp_nmstr& s) _NOEXCEPT
71    : str_(s.str_)
72{
73    __sync_add_and_fetch(&count(), 1);
74}
75
76__libcpp_nmstr&
77__libcpp_nmstr::operator=(const __libcpp_nmstr& s) _NOEXCEPT
78{
79    const char* p = str_;
80    str_ = s.str_;
81    __sync_add_and_fetch(&count(), 1);
82    if (__sync_add_and_fetch((count_t*)(p-sizeof(count_t)), count_t(-1)) < 0)
83        delete [] (p-offset);
84    return *this;
85}
86
87inline
88__libcpp_nmstr::~__libcpp_nmstr()
89{
90    if (__sync_add_and_fetch(&count(), count_t(-1)) < 0)
91        delete [] (str_ - offset);
92}
93
94}
95
96#if ! defined(_LIBCPP_MSVC)
97#pragma GCC visibility pop
98#endif
99
100namespace std  // purposefully not using versioning namespace
101{
102
103logic_error::logic_error(const string& msg)
104{
105    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
106    ::new(&s) __libcpp_nmstr(msg.c_str());
107}
108
109logic_error::logic_error(const char* msg)
110{
111    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
112    ::new(&s) __libcpp_nmstr(msg);
113}
114
115logic_error::logic_error(const logic_error& le) _NOEXCEPT
116{
117    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
118    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
119}
120
121logic_error&
122logic_error::operator=(const logic_error& le) _NOEXCEPT
123{
124    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
125    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
126    s1 = s2;
127    return *this;
128}
129
130#if !defined(_LIBCPPABI_VERSION) && !defined(LIBSTDCXX)
131
132logic_error::~logic_error() _NOEXCEPT
133{
134    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
135    s.~__libcpp_nmstr();
136}
137
138const char*
139logic_error::what() const _NOEXCEPT
140{
141    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
142    return s.c_str();
143}
144
145#endif
146
147runtime_error::runtime_error(const string& msg)
148{
149    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
150    ::new(&s) __libcpp_nmstr(msg.c_str());
151}
152
153runtime_error::runtime_error(const char* msg)
154{
155    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
156    ::new(&s) __libcpp_nmstr(msg);
157}
158
159runtime_error::runtime_error(const runtime_error& le) _NOEXCEPT
160{
161    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
162    ::new(&s) __libcpp_nmstr((const __libcpp_nmstr&)le.__imp_);
163}
164
165runtime_error&
166runtime_error::operator=(const runtime_error& le) _NOEXCEPT
167{
168    __libcpp_nmstr& s1 = (__libcpp_nmstr&)__imp_;
169    const __libcpp_nmstr& s2 = (const __libcpp_nmstr&)le.__imp_;
170    s1 = s2;
171    return *this;
172}
173
174#if !defined(_LIBCPPABI_VERSION) && !defined(LIBSTDCXX)
175
176runtime_error::~runtime_error() _NOEXCEPT
177{
178    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
179    s.~__libcpp_nmstr();
180}
181
182const char*
183runtime_error::what() const _NOEXCEPT
184{
185    __libcpp_nmstr& s = (__libcpp_nmstr&)__imp_;
186    return s.c_str();
187}
188
189domain_error::~domain_error() _NOEXCEPT {}
190invalid_argument::~invalid_argument() _NOEXCEPT {}
191length_error::~length_error() _NOEXCEPT {}
192out_of_range::~out_of_range() _NOEXCEPT {}
193
194range_error::~range_error() _NOEXCEPT {}
195overflow_error::~overflow_error() _NOEXCEPT {}
196underflow_error::~underflow_error() _NOEXCEPT {}
197
198#endif
199
200}  // std
201