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 #include <stdio.h>
11
12 #include "exception"
13 #include "new"
14
15 #ifndef __has_include
16 #define __has_include(inc) 0
17 #endif
18
19 #if defined(__APPLE__) && !defined(LIBCXXRT)
20 #include <cxxabi.h>
21
22 using namespace __cxxabiv1;
23 #define HAVE_DEPENDENT_EH_ABI 1
24 #ifndef _LIBCPPABI_VERSION
25 using namespace __cxxabiapple;
26 // On Darwin, there are two STL shared libraries and a lower level ABI
27 // shared library. The globals holding the current terminate handler and
28 // current unexpected handler are in the ABI library.
29 #define __terminate_handler __cxxabiapple::__cxa_terminate_handler
30 #define __unexpected_handler __cxxabiapple::__cxa_unexpected_handler
31 #endif // _LIBCPPABI_VERSION
32 #elif defined(LIBCXXRT) || __has_include(<cxxabi.h>)
33 #include <cxxabi.h>
34 using namespace __cxxabiv1;
35 #if defined(LIBCXXRT) || defined(_LIBCPPABI_VERSION)
36 #define HAVE_DEPENDENT_EH_ABI 1
37 #endif
38 #elif !defined(__GLIBCXX__) // __has_include(<cxxabi.h>)
39 static std::terminate_handler __terminate_handler;
40 static std::unexpected_handler __unexpected_handler;
41 #endif // __has_include(<cxxabi.h>)
42
43 namespace std
44 {
45
46 #if !defined(LIBCXXRT) && !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)
47
48 // libcxxrt provides implementations of these functions itself.
49 unexpected_handler
set_unexpected(unexpected_handler func)50 set_unexpected(unexpected_handler func) _NOEXCEPT
51 {
52 return __sync_lock_test_and_set(&__unexpected_handler, func);
53 }
54
55 unexpected_handler
get_unexpected()56 get_unexpected() _NOEXCEPT
57 {
58 return __sync_fetch_and_add(&__unexpected_handler, (unexpected_handler)0);
59 }
60
61 _LIBCPP_NORETURN
62 void
unexpected()63 unexpected()
64 {
65 (*get_unexpected())();
66 // unexpected handler should not return
67 terminate();
68 }
69
70 terminate_handler
set_terminate(terminate_handler func)71 set_terminate(terminate_handler func) _NOEXCEPT
72 {
73 return __sync_lock_test_and_set(&__terminate_handler, func);
74 }
75
76 terminate_handler
get_terminate()77 get_terminate() _NOEXCEPT
78 {
79 return __sync_fetch_and_add(&__terminate_handler, (terminate_handler)0);
80 }
81
82 #ifndef __EMSCRIPTEN__ // We provide this in JS
83 _LIBCPP_NORETURN
84 void
terminate()85 terminate() _NOEXCEPT
86 {
87 #ifndef _LIBCPP_NO_EXCEPTIONS
88 try
89 {
90 #endif // _LIBCPP_NO_EXCEPTIONS
91 (*get_terminate())();
92 // handler should not return
93 printf("terminate_handler unexpectedly returned\n");
94 ::abort();
95 #ifndef _LIBCPP_NO_EXCEPTIONS
96 }
97 catch (...)
98 {
99 // handler should not throw exception
100 printf("terminate_handler unexpectedly threw an exception\n");
101 ::abort();
102 }
103 #endif // _LIBCPP_NO_EXCEPTIONS
104 }
105 #endif // !__EMSCRIPTEN__
106 #endif // !defined(LIBCXXRT) && !defined(_LIBCPPABI_VERSION)
107
108 #if !defined(LIBCXXRT) && !defined(__GLIBCXX__) && !defined(__EMSCRIPTEN__)
uncaught_exception()109 bool uncaught_exception() _NOEXCEPT
110 {
111 #if defined(__APPLE__) || defined(_LIBCPPABI_VERSION)
112 // on Darwin, there is a helper function so __cxa_get_globals is private
113 return __cxa_uncaught_exception();
114 #else // __APPLE__
115 # if defined(_MSC_VER) && ! defined(__clang__)
116 _LIBCPP_WARNING("uncaught_exception not yet implemented")
117 # else
118 # warning uncaught_exception not yet implemented
119 # endif
120 printf("uncaught_exception not yet implemented\n");
121 ::abort();
122 #endif // __APPLE__
123 }
124
125
126 #ifndef _LIBCPPABI_VERSION
127
~exception()128 exception::~exception() _NOEXCEPT
129 {
130 }
131
what() const132 const char* exception::what() const _NOEXCEPT
133 {
134 return "std::exception";
135 }
136
137 #endif // _LIBCPPABI_VERSION
138 #endif //LIBCXXRT
139 #if !defined(_LIBCPPABI_VERSION) && !defined(__GLIBCXX__)
140
~bad_exception()141 bad_exception::~bad_exception() _NOEXCEPT
142 {
143 }
144
what() const145 const char* bad_exception::what() const _NOEXCEPT
146 {
147 return "std::bad_exception";
148 }
149
150 #endif
151
152 #if defined(__GLIBCXX__)
153
154 // libsupc++ does not implement the dependent EH ABI and the functionality
155 // it uses to implement std::exception_ptr (which it declares as an alias of
156 // std::__exception_ptr::exception_ptr) is not directly exported to clients. So
157 // we have little choice but to hijack std::__exception_ptr::exception_ptr's
158 // (which fortunately has the same layout as our std::exception_ptr) copy
159 // constructor, assignment operator and destructor (which are part of its
160 // stable ABI), and its rethrow_exception(std::__exception_ptr::exception_ptr)
161 // function.
162
163 namespace __exception_ptr
164 {
165
166 struct exception_ptr
167 {
168 void* __ptr_;
169
170 exception_ptr(const exception_ptr&) _NOEXCEPT;
171 exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
172 ~exception_ptr() _NOEXCEPT;
173 };
174
175 }
176
177 _LIBCPP_NORETURN void rethrow_exception(__exception_ptr::exception_ptr);
178
179 #endif
180
~exception_ptr()181 exception_ptr::~exception_ptr() _NOEXCEPT
182 {
183 #if HAVE_DEPENDENT_EH_ABI
184 __cxa_decrement_exception_refcount(__ptr_);
185 #elif defined(__GLIBCXX__)
186 reinterpret_cast<__exception_ptr::exception_ptr*>(this)->~exception_ptr();
187 #else
188 # if defined(_MSC_VER) && ! defined(__clang__)
189 _LIBCPP_WARNING("exception_ptr not yet implemented")
190 # else
191 # warning exception_ptr not yet implemented
192 # endif
193 printf("exception_ptr not yet implemented\n");
194 ::abort();
195 #endif
196 }
197
exception_ptr(const exception_ptr & other)198 exception_ptr::exception_ptr(const exception_ptr& other) _NOEXCEPT
199 : __ptr_(other.__ptr_)
200 {
201 #if HAVE_DEPENDENT_EH_ABI
202 __cxa_increment_exception_refcount(__ptr_);
203 #elif defined(__GLIBCXX__)
204 new (reinterpret_cast<void*>(this)) __exception_ptr::exception_ptr(
205 reinterpret_cast<const __exception_ptr::exception_ptr&>(other));
206 #else
207 # if defined(_MSC_VER) && ! defined(__clang__)
208 _LIBCPP_WARNING("exception_ptr not yet implemented")
209 # else
210 # warning exception_ptr not yet implemented
211 # endif
212 printf("exception_ptr not yet implemented\n");
213 ::abort();
214 #endif
215 }
216
operator =(const exception_ptr & other)217 exception_ptr& exception_ptr::operator=(const exception_ptr& other) _NOEXCEPT
218 {
219 #if HAVE_DEPENDENT_EH_ABI
220 if (__ptr_ != other.__ptr_)
221 {
222 __cxa_increment_exception_refcount(other.__ptr_);
223 __cxa_decrement_exception_refcount(__ptr_);
224 __ptr_ = other.__ptr_;
225 }
226 return *this;
227 #elif defined(__GLIBCXX__)
228 *reinterpret_cast<__exception_ptr::exception_ptr*>(this) =
229 reinterpret_cast<const __exception_ptr::exception_ptr&>(other);
230 return *this;
231 #else
232 # if defined(_MSC_VER) && ! defined(__clang__)
233 _LIBCPP_WARNING("exception_ptr not yet implemented")
234 # else
235 # warning exception_ptr not yet implemented
236 # endif
237 printf("exception_ptr not yet implemented\n");
238 ::abort();
239 #endif
240 }
241
nested_exception()242 nested_exception::nested_exception() _NOEXCEPT
243 : __ptr_(current_exception())
244 {
245 }
246
247 #if !defined(__GLIBCXX__)
248
~nested_exception()249 nested_exception::~nested_exception() _NOEXCEPT
250 {
251 }
252
253 #endif
254
255 _LIBCPP_NORETURN
256 void
rethrow_nested() const257 nested_exception::rethrow_nested() const
258 {
259 if (__ptr_ == nullptr)
260 terminate();
261 rethrow_exception(__ptr_);
262 }
263
264 #if !defined(__GLIBCXX__)
265
current_exception()266 exception_ptr current_exception() _NOEXCEPT
267 {
268 #if HAVE_DEPENDENT_EH_ABI
269 // be nicer if there was a constructor that took a ptr, then
270 // this whole function would be just:
271 // return exception_ptr(__cxa_current_primary_exception());
272 exception_ptr ptr;
273 ptr.__ptr_ = __cxa_current_primary_exception();
274 return ptr;
275 #else
276 # if defined(_MSC_VER) && ! defined(__clang__)
277 _LIBCPP_WARNING( "exception_ptr not yet implemented" )
278 # else
279 # warning exception_ptr not yet implemented
280 # endif
281 printf("exception_ptr not yet implemented\n");
282 ::abort();
283 #endif
284 }
285
286 #endif // !__GLIBCXX__
287
288 _LIBCPP_NORETURN
rethrow_exception(exception_ptr p)289 void rethrow_exception(exception_ptr p)
290 {
291 #if HAVE_DEPENDENT_EH_ABI
292 __cxa_rethrow_primary_exception(p.__ptr_);
293 // if p.__ptr_ is NULL, above returns so we terminate
294 terminate();
295 #elif defined(__GLIBCXX__)
296 rethrow_exception(reinterpret_cast<__exception_ptr::exception_ptr&>(p));
297 #else
298 # if defined(_MSC_VER) && ! defined(__clang__)
299 _LIBCPP_WARNING("exception_ptr not yet implemented")
300 # else
301 # warning exception_ptr not yet implemented
302 # endif
303 printf("exception_ptr not yet implemented\n");
304 ::abort();
305 #endif
306 }
307 } // std
308