exception.cpp revision 246468 
1//===------------------------ exception.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#include <stdlib.h>
10
11#include "exception"
12
13#ifndef __has_include
14#define __has_include(inc) 0
15#endif
16
17#if __APPLE__
18  #include <cxxabi.h>
19
20  using namespace __cxxabiv1;
21  #define HAVE_DEPENDENT_EH_ABI 1
22  #ifndef _LIBCPPABI_VERSION
23    using namespace __cxxabiapple;
24    // On Darwin, there are two STL shared libraries and a lower level ABI
25    // shared libray.  The globals holding the current terminate handler and
26    // current unexpected handler are in the ABI library.
27    #define __terminate_handler  __cxxabiapple::__cxa_terminate_handler
28    #define __unexpected_handler __cxxabiapple::__cxa_unexpected_handler
29  #endif  // _LIBCPPABI_VERSION
30#elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
31  #include <cxxabi.h>
32  using namespace __cxxabiv1;
33  #if defined(LIBCXXRT) || defined(_LIBCPPABI_VERSION)
34    #define HAVE_DEPENDENT_EH_ABI 1
35  #endif
36#elif !defined(__GLIBCXX__) // __has_include(<cxxabi.h>)
37  static std::terminate_handler  __terminate_handler;
38  static std::unexpected_handler __unexpected_handler;
39#endif // __has_include(<cxxabi.h>)
40
41namespace std
42{
43
44#if !defined(LIBCXXRT) && !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)
45
46// libcxxrt provides implementations of these functions itself.
47unexpected_handler
48set_unexpected(unexpected_handler func) _NOEXCEPT
49{
50    return __sync_lock_test_and_set(&__unexpected_handler, func);
51}
52
53unexpected_handler
54get_unexpected() _NOEXCEPT
55{
56    return __sync_fetch_and_add(&__unexpected_handler, (unexpected_handler)0);
57}
58
59_LIBCPP_NORETURN
60void
61unexpected()
62{
63    (*get_unexpected())();
64    // unexpected handler should not return
65    terminate();
66}
67
68terminate_handler
69set_terminate(terminate_handler func) _NOEXCEPT
70{
71    return __sync_lock_test_and_set(&__terminate_handler, func);
72}
73
74terminate_handler
75get_terminate() _NOEXCEPT
76{
77    return __sync_fetch_and_add(&__terminate_handler, (terminate_handler)0);
78}
79
80_LIBCPP_NORETURN
81void
82terminate() _NOEXCEPT
83{
84#ifndef _LIBCPP_NO_EXCEPTIONS
85    try
86    {
87#endif  // _LIBCPP_NO_EXCEPTIONS
88        (*get_terminate())();
89        // handler should not return
90        ::abort ();
91#ifndef _LIBCPP_NO_EXCEPTIONS
92    }
93    catch (...)
94    {
95        // handler should not throw exception
96        ::abort ();
97    }
98#endif  // _LIBCPP_NO_EXCEPTIONS
99}
100#endif // !defined(LIBCXXRT) && !defined(_LIBCPPABI_VERSION)
101
102#if !defined(LIBCXXRT) && !defined(__GLIBCXX__)
103bool uncaught_exception() _NOEXCEPT
104{
105#if __APPLE__ || defined(_LIBCPPABI_VERSION)
106    // on Darwin, there is a helper function so __cxa_get_globals is private
107    return __cxa_uncaught_exception();
108#else  // __APPLE__
109    #warning uncaught_exception not yet implemented
110    ::abort();
111#endif  // __APPLE__
112}
113
114#ifndef _LIBCPPABI_VERSION
115
116exception::~exception() _NOEXCEPT
117{
118}
119
120const char* exception::what() const _NOEXCEPT
121{
122  return "std::exception";
123}
124
125#endif  // _LIBCPPABI_VERSION
126#endif //LIBCXXRT
127#if !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)
128
129bad_exception::~bad_exception() _NOEXCEPT
130{
131}
132
133const char* bad_exception::what() const _NOEXCEPT
134{
135  return "std::bad_exception";
136}
137
138#endif
139
140
141exception_ptr::~exception_ptr() _NOEXCEPT
142{
143#if HAVE_DEPENDENT_EH_ABI
144    __cxa_decrement_exception_refcount(__ptr_);
145#else
146    #warning exception_ptr not yet implemented
147    ::abort();
148#endif  // __APPLE__
149}
150
151exception_ptr::exception_ptr(const exception_ptr& other) _NOEXCEPT
152    : __ptr_(other.__ptr_)
153{
154#if HAVE_DEPENDENT_EH_ABI
155    __cxa_increment_exception_refcount(__ptr_);
156#else
157    #warning exception_ptr not yet implemented
158    ::abort();
159#endif  // __APPLE__
160}
161
162exception_ptr& exception_ptr::operator=(const exception_ptr& other) _NOEXCEPT
163{
164#if HAVE_DEPENDENT_EH_ABI
165    if (__ptr_ != other.__ptr_)
166    {
167        __cxa_increment_exception_refcount(other.__ptr_);
168        __cxa_decrement_exception_refcount(__ptr_);
169        __ptr_ = other.__ptr_;
170    }
171    return *this;
172#else  // __APPLE__
173    #warning exception_ptr not yet implemented
174    ::abort();
175#endif  // __APPLE__
176}
177
178nested_exception::nested_exception() _NOEXCEPT
179    : __ptr_(current_exception())
180{
181}
182
183nested_exception::~nested_exception() _NOEXCEPT
184{
185}
186
187_LIBCPP_NORETURN
188void
189nested_exception::rethrow_nested() const
190{
191    if (__ptr_ == nullptr)
192        terminate();
193    rethrow_exception(__ptr_);
194}
195
196
197exception_ptr current_exception() _NOEXCEPT
198{
199#if HAVE_DEPENDENT_EH_ABI
200    // be nicer if there was a constructor that took a ptr, then
201    // this whole function would be just:
202    //    return exception_ptr(__cxa_current_primary_exception());
203    exception_ptr ptr;
204    ptr.__ptr_ = __cxa_current_primary_exception();
205    return ptr;
206#else  // __APPLE__
207    #warning exception_ptr not yet implemented
208    ::abort();
209#endif  // __APPLE__
210}
211
212_LIBCPP_NORETURN
213void rethrow_exception(exception_ptr p)
214{
215#if HAVE_DEPENDENT_EH_ABI
216    __cxa_rethrow_primary_exception(p.__ptr_);
217    // if p.__ptr_ is NULL, above returns so we terminate
218    terminate();
219#else  // __APPLE__
220    #warning exception_ptr not yet implemented
221    ::abort();
222#endif  // __APPLE__
223}
224} // std
225