1 // Methods for Exception Support for -*- C++ -*-
3 // Copyright (C) 2014-2018 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
26 // ISO C++ 14882: 19.1 Exception classes
29 // Enable hooks for support for the Transactional Memory TS (N4514).
30 #define _GLIBCXX_TM_TS_INTERNAL
32 _txnal_cow_string_C1_for_exceptions(void* that
, const char* s
, void* exc
);
34 _txnal_cow_string_c_str(const void* that
);
36 _txnal_cow_string_D1(void* that
);
38 _txnal_cow_string_D1_commit(void* that
);
40 _txnal_logic_error_get_msg(void* e
);
42 _txnal_runtime_error_get_msg(void* e
);
44 // All exception classes still use the classic COW std::string.
45 #define _GLIBCXX_USE_CXX11_ABI 0
46 #define _GLIBCXX_DEFINE_STDEXCEPT_COPY_OPS 1
47 #define __cow_string __cow_stringxxx
49 #include <system_error>
52 namespace std
_GLIBCXX_VISIBILITY(default)
54 _GLIBCXX_BEGIN_NAMESPACE_VERSION
56 // Copy constructors and assignment operators defined using COW std::string
58 logic_error::logic_error(const logic_error
& e
) noexcept
59 : exception(e
), _M_msg(e
._M_msg
) { }
61 logic_error
& logic_error::operator=(const logic_error
& e
) noexcept
62 { _M_msg
= e
._M_msg
; return *this; }
64 runtime_error::runtime_error(const runtime_error
& e
) noexcept
65 : exception(e
), _M_msg(e
._M_msg
) { }
68 runtime_error::operator=(const runtime_error
& e
) noexcept
69 { _M_msg
= e
._M_msg
; return *this; }
71 // New C++11 constructors:
73 logic_error::logic_error(const char* __arg
)
74 : exception(), _M_msg(__arg
) { }
76 domain_error::domain_error(const char* __arg
)
77 : logic_error(__arg
) { }
79 invalid_argument::invalid_argument(const char* __arg
)
80 : logic_error(__arg
) { }
82 length_error::length_error(const char* __arg
)
83 : logic_error(__arg
) { }
85 out_of_range::out_of_range(const char* __arg
)
86 : logic_error(__arg
) { }
88 runtime_error::runtime_error(const char* __arg
)
89 : exception(), _M_msg(__arg
) { }
91 range_error::range_error(const char* __arg
)
92 : runtime_error(__arg
) { }
94 overflow_error::overflow_error(const char* __arg
)
95 : runtime_error(__arg
) { }
97 underflow_error::underflow_error(const char* __arg
)
98 : runtime_error(__arg
) { }
100 #if _GLIBCXX_USE_DUAL_ABI
101 // Converting constructor from COW std::string to SSO string.
102 __sso_string::__sso_string(const string
& s
)
103 : __sso_string(s
.c_str(), s
.length()) { }
105 // Redefine __cow_string so that we can define and export its members
106 // in terms of the COW std::string.
111 char _M_bytes
[sizeof(_M_p
)];
116 __cow_string(const std::string
& s
);
117 __cow_string(const char*, size_t n
);
118 __cow_string(const __cow_string
&) noexcept
;
119 __cow_string
& operator=(const __cow_string
&) noexcept
;
121 __cow_string(__cow_string
&&) noexcept
;
122 __cow_string
& operator=(__cow_string
&&) noexcept
;
125 __cow_string::__cow_string() : _M_str() { }
127 __cow_string::__cow_string(const std::string
& s
) : _M_str(s
) { }
129 __cow_string::__cow_string(const char* s
, size_t n
) : _M_str(s
, n
) { }
131 __cow_string::__cow_string(const __cow_string
& s
) noexcept
132 : _M_str(s
._M_str
) { }
135 __cow_string::operator=(const __cow_string
& s
) noexcept
141 __cow_string::~__cow_string() { _M_str
.~basic_string(); }
143 __cow_string::__cow_string(__cow_string
&& s
) noexcept
144 : _M_str(std::move(s
._M_str
)) { }
147 __cow_string::operator=(__cow_string
&& s
) noexcept
149 _M_str
= std::move(s
._M_str
);
153 static_assert(sizeof(__cow_string
) == sizeof(std::string
),
154 "sizeof(std::string) has changed");
155 static_assert(alignof(__cow_string
) == alignof(std::string
),
156 "alignof(std::string) has changed");
159 // Return error_category::message() as an SSO string
161 error_category::_M_message(int i
) const
163 string msg
= this->message(i
);
164 return {msg
.c_str(), msg
.length()};
167 _GLIBCXX_END_NAMESPACE_VERSION
170 // Support for the Transactional Memory TS (N4514).
172 // logic_error and runtime_error both carry a message in the form of a COW
173 // string. This COW string is never made visible to users of the exception
174 // because what() returns a C string. The COW string can be constructed as
175 // either a copy of a COW string of another logic_error/runtime_error, or
176 // using a C string or SSO string; thus, the COW string's _Rep is only
177 // accessed by logic_error operations. We control all txnal clones of those
178 // operations and thus can ensure that _Rep is never accessed transactionally.
179 // Furthermore, _Rep will always have been allocated or deallocated via
180 // global new or delete, so nontransactional writes we do to _Rep cannot
181 // interfere with transactional accesses.
183 // We depend on having support for referencing functions declared weak that
184 // are not defined by us. Without such support, the exceptions will not be
185 // declared transaction-safe, so we just don't provide transactional clones
187 #if _GLIBCXX_USE_WEAK_REF
191 #ifndef _GLIBCXX_MANGLE_SIZE_T
192 #error Mangled name of size_t type not defined.
194 #define CONCAT1(x,y) x##y
195 #define CONCAT(x,y) CONCAT1(x,y)
196 #define _ZGTtnaX CONCAT(_ZGTtna,_GLIBCXX_MANGLE_SIZE_T)
199 /* Only for 32-bit x86. */
200 # define ITM_REGPARM __attribute__((regparm(2)))
205 // Declare all libitm symbols we rely on, but make them weak so that we do
206 // not depend on libitm.
207 extern void* _ZGTtnaX (size_t sz
) __attribute__((weak
));
208 extern void _ZGTtdlPv (void* ptr
) __attribute__((weak
));
209 extern uint8_t _ITM_RU1(const uint8_t *p
)
210 ITM_REGPARM
__attribute__((weak
));
211 extern uint16_t _ITM_RU2(const uint16_t *p
)
212 ITM_REGPARM
__attribute__((weak
));
213 extern uint32_t _ITM_RU4(const uint32_t *p
)
214 ITM_REGPARM
__attribute__((weak
));
215 extern uint64_t _ITM_RU8(const uint64_t *p
)
216 ITM_REGPARM
__attribute__((weak
));
217 extern void _ITM_memcpyRtWn(void *, const void *, size_t)
218 ITM_REGPARM
__attribute__((weak
));
219 extern void _ITM_memcpyRnWt(void *, const void *, size_t)
220 ITM_REGPARM
__attribute__((weak
));
221 extern void _ITM_addUserCommitAction(void (*)(void *), uint64_t, void *)
222 ITM_REGPARM
__attribute__((weak
));
226 // A transactional version of basic_string::basic_string(const char *s)
227 // that also notifies the TM runtime about allocations belonging to this
230 _txnal_cow_string_C1_for_exceptions(void* that
, const char* s
,
231 void *exc
__attribute__((unused
)))
233 typedef std::basic_string
<char> bs_type
;
234 bs_type
*bs
= (bs_type
*) that
;
236 // First, do a transactional strlen, but including the trailing zero.
237 bs_type::size_type len
= 1;
238 for (const char *ss
= s
; _ITM_RU1((const uint8_t*) ss
) != 0; ss
++, len
++);
241 // Allocate memory for the string and the refcount. We use the
242 // transactional clone of global new[]; if this throws, it will do so in a
243 // transaction-compatible way.
244 // The allocation belongs to this exception, so tell the runtime about it.
245 // TODO Once this is supported, link the following allocation to this
246 // exception: void *prev = _ITM_setAssociatedException(exc);
250 rep
= (bs_type::_Rep
*) _ZGTtnaX (len
+ sizeof (bs_type::_Rep
));
254 // Pop the association with this exception.
255 // TODO Once this is supported, link the following allocation to this
256 // exception: _ITM_setAssociatedException(prev);
257 // We do not need to instrument a rethrow.
258 __throw_exception_again
;
260 // Pop the association with this exception.
261 // TODO Once this is supported, link the following allocation to this
262 // exception: _ITM_setAssociatedException(prev);
264 // Now initialize the rest of the string and copy the C string. The memory
265 // will be freshly allocated, so nontransactional accesses are sufficient,
266 // including the writes when copying the string (see above).
267 rep
->_M_set_sharable();
268 rep
->_M_length
= rep
->_M_capacity
= len
- 1;
269 _ITM_memcpyRtWn(rep
->_M_refdata(), s
, len
);
270 new (&bs
->_M_dataplus
) bs_type::_Alloc_hider(rep
->_M_refdata(),
271 bs_type::allocator_type());
274 static void* txnal_read_ptr(void* const * ptr
)
276 static_assert(sizeof(uint64_t) == sizeof(void*)
277 || sizeof(uint32_t) == sizeof(void*)
278 || sizeof(uint16_t) == sizeof(void*),
279 "Pointers must be 16 bits, 32 bits or 64 bits wide");
280 #if __UINTPTR_MAX__ == __UINT64_MAX__
281 return (void*)_ITM_RU8((const uint64_t*)ptr
);
282 #elif __UINTPTR_MAX__ == __UINT32_MAX__
283 return (void*)_ITM_RU4((const uint32_t*)ptr
);
285 return (void*)_ITM_RU2((const uint16_t*)ptr
);
289 // We must access the data pointer in the COW string transactionally because
290 // another transaction can delete the string and reuse the memory.
292 _txnal_cow_string_c_str(const void* that
)
294 typedef std::basic_string
<char> bs_type
;
295 const bs_type
*bs
= (const bs_type
*) that
;
297 return (const char*) txnal_read_ptr((void**)&bs
->_M_dataplus
._M_p
);
300 #if _GLIBCXX_USE_DUAL_ABI
302 _txnal_sso_string_c_str(const void* that
)
304 return (const char*) txnal_read_ptr(
305 (void* const*)const_cast<char* const*>(
306 &((const std::__sso_string
*) that
)->_M_s
._M_p
));
311 _txnal_cow_string_D1_commit(void* data
)
313 typedef std::basic_string
<char> bs_type
;
314 bs_type::_Rep
*rep
= (bs_type::_Rep
*) data
;
315 rep
->_M_dispose(bs_type::allocator_type());
319 _txnal_cow_string_D1(void* that
)
321 typedef std::basic_string
<char> bs_type
;
322 bs_type::_Rep
*rep
= reinterpret_cast<bs_type::_Rep
*>(
323 const_cast<char*>(_txnal_cow_string_c_str(that
))) - 1;
325 // The string can be shared, in which case we would need to decrement the
326 // reference count. We cannot undo that because we might lose the string
327 // otherwise. Therefore, we register a commit action that will dispose of
328 // the string's _Rep.
329 enum {_ITM_noTransactionId
= 1};
330 _ITM_addUserCommitAction(_txnal_cow_string_D1_commit
, _ITM_noTransactionId
,
335 _txnal_logic_error_get_msg(void* e
)
337 std::logic_error
* le
= (std::logic_error
*) e
;
342 _txnal_runtime_error_get_msg(void* e
)
344 std::runtime_error
* le
= (std::runtime_error
*) e
;
348 // The constructors are only declared transaction-safe if the C++11 ABI is
349 // used for std::string and the exception classes use a COW string internally.
350 // A user must not call these constructors otherwise; if they do, it will
351 // result in undefined behavior, which is in this case not initializing this
353 #if _GLIBCXX_USE_DUAL_ABI
354 #define CTORS_FROM_SSOSTRING(NAME, CLASS, BASE) \
356 _ZGTtNSt##NAME##C1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE( \
357 CLASS* that, const std::__sso_string& s) \
360 _ITM_memcpyRnWt(that, &e, sizeof(CLASS)); \
361 /* Get the C string from the SSO string. */ \
362 _txnal_cow_string_C1_for_exceptions(_txnal_##BASE##_get_msg(that), \
363 _txnal_sso_string_c_str(&s), that); \
366 _ZGTtNSt##NAME##C2ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE( \
367 CLASS*, const std::__sso_string&) __attribute__((alias \
369 "C1ERKNSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEE")));
371 #define CTORS_FROM_SSOSTRING(NAME, CLASS, BASE)
374 // This macro defines transaction constructors and destructors for a specific
375 // exception class. NAME is the variable part of the mangled name, CLASS is
376 // the class name, and BASE must be logic_error or runtime_error (which is
377 // then used to call the proper friend function that can return a pointer to
378 // the _M_msg member declared by the given (base) class).
379 #define CTORDTOR(NAME, CLASS, BASE) \
381 _ZGTtNSt##NAME##C1EPKc (CLASS* that, const char* s) \
383 /* This will use the singleton _Rep for an empty string and just \
384 point to it instead of allocating memory. Thus, we can use it as \
385 source, copy it into the object we are constructing, and then \
386 construct the COW string in the latter manually. Note that the \
387 exception classes will not be declared transaction_safe if the \
388 shared empty _Rep is disabled with --enable-fully-dynamic-string \
389 (in which case _GLIBCXX_FULLY_DYNAMIC_STRING is nonzero). */ \
391 _ITM_memcpyRnWt(that, &e, sizeof(CLASS)); \
392 _txnal_cow_string_C1_for_exceptions(_txnal_##BASE##_get_msg(that), \
396 _ZGTtNSt##NAME##C2EPKc (CLASS*, const char*) \
397 __attribute__((alias ("_ZGTtNSt" #NAME "C1EPKc"))); \
398 CTORS_FROM_SSOSTRING(NAME, CLASS, BASE) \
400 _ZGTtNSt##NAME##D1Ev(CLASS* that) \
401 { _txnal_cow_string_D1(_txnal_##BASE##_get_msg(that)); } \
403 _ZGTtNSt##NAME##D2Ev(CLASS*) \
404 __attribute__((alias ("_ZGTtNSt" #NAME "D1Ev"))); \
406 _ZGTtNSt##NAME##D0Ev(CLASS* that) \
408 _ZGTtNSt##NAME##D1Ev(that); \
412 // Now create all transactional constructors and destructors, as well as the
413 // two virtual what() functions.
416 CTORDTOR(11logic_error
, std::logic_error
, logic_error
)
419 _ZGTtNKSt11logic_error4whatEv(const std::logic_error
* that
)
421 return _txnal_cow_string_c_str(_txnal_logic_error_get_msg(
422 const_cast<std::logic_error
*>(that
)));
425 CTORDTOR(12domain_error
, std::domain_error
, logic_error
)
426 CTORDTOR(16invalid_argument
, std::invalid_argument
, logic_error
)
427 CTORDTOR(12length_error
, std::length_error
, logic_error
)
428 CTORDTOR(12out_of_range
, std::out_of_range
, logic_error
)
431 CTORDTOR(13runtime_error
, std::runtime_error
, runtime_error
)
434 _ZGTtNKSt13runtime_error4whatEv(const std::runtime_error
* that
)
436 return _txnal_cow_string_c_str(_txnal_runtime_error_get_msg(
437 const_cast<std::runtime_error
*>(that
)));
440 CTORDTOR(11range_error
, std::range_error
, runtime_error
)
441 CTORDTOR(14overflow_error
, std::overflow_error
, runtime_error
)
442 CTORDTOR(15underflow_error
, std::underflow_error
, runtime_error
)
446 #endif // _GLIBCXX_USE_WEAK_REF