xref: /freebsd/contrib/llvm-project/libcxx/src/system_error.cpp (revision bdd1243df58e60e85101c09001d9812a789b6bc4)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include <__config>
10 #ifdef _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
11 #   define _LIBCPP_ERROR_CATEGORY_DEFINE_LEGACY_INLINE_FUNCTIONS
12 #endif
13 
14 #include <__assert>
15 #include <cerrno>
16 #include <cstdio>
17 #include <cstdlib>
18 #include <cstring>
19 #include <string>
20 #include <string.h>
21 #include <system_error>
22 
23 #include "include/config_elast.h"
24 
25 #if defined(__ANDROID__)
26 #include <android/api-level.h>
27 #endif
28 
29 _LIBCPP_BEGIN_NAMESPACE_STD
30 
31 // class error_category
32 
33 #if defined(_LIBCPP_ERROR_CATEGORY_DEFINE_LEGACY_INLINE_FUNCTIONS)
34 error_category::error_category() noexcept
35 {
36 }
37 #endif
38 
39 error_category::~error_category() noexcept
40 {
41 }
42 
43 error_condition
44 error_category::default_error_condition(int ev) const noexcept
45 {
46     return error_condition(ev, *this);
47 }
48 
49 bool
50 error_category::equivalent(int code, const error_condition& condition) const noexcept
51 {
52     return default_error_condition(code) == condition;
53 }
54 
55 bool
56 error_category::equivalent(const error_code& code, int condition) const noexcept
57 {
58     return *this == code.category() && code.value() == condition;
59 }
60 
61 #if !defined(_LIBCPP_HAS_NO_THREADS)
62 namespace {
63 
64 //  GLIBC also uses 1024 as the maximum buffer size internally.
65 constexpr size_t strerror_buff_size = 1024;
66 
67 string do_strerror_r(int ev);
68 
69 #if defined(_LIBCPP_MSVCRT_LIKE)
70 string do_strerror_r(int ev) {
71   char buffer[strerror_buff_size];
72   if (::strerror_s(buffer, strerror_buff_size, ev) == 0)
73     return string(buffer);
74   std::snprintf(buffer, strerror_buff_size, "unknown error %d", ev);
75   return string(buffer);
76 }
77 #else
78 
79 // Only one of the two following functions will be used, depending on
80 // the return type of strerror_r:
81 
82 // For the GNU variant, a char* return value:
83 __attribute__((unused)) const char *
84 handle_strerror_r_return(char *strerror_return, char *buffer) {
85   // GNU always returns a string pointer in its return value. The
86   // string might point to either the input buffer, or a static
87   // buffer, but we don't care which.
88   return strerror_return;
89 }
90 
91 // For the POSIX variant: an int return value.
92 __attribute__((unused)) const char *
93 handle_strerror_r_return(int strerror_return, char *buffer) {
94   // The POSIX variant either:
95   // - fills in the provided buffer and returns 0
96   // - returns a positive error value, or
97   // - returns -1 and fills in errno with an error value.
98   if (strerror_return == 0)
99     return buffer;
100 
101   // Only handle EINVAL. Other errors abort.
102   int new_errno = strerror_return == -1 ? errno : strerror_return;
103   if (new_errno == EINVAL)
104     return "";
105 
106   _LIBCPP_ASSERT(new_errno == ERANGE, "unexpected error from ::strerror_r");
107   // FIXME maybe? 'strerror_buff_size' is likely to exceed the
108   // maximum error size so ERANGE shouldn't be returned.
109   std::abort();
110 }
111 
112 // This function handles both GNU and POSIX variants, dispatching to
113 // one of the two above functions.
114 string do_strerror_r(int ev) {
115     char buffer[strerror_buff_size];
116     // Preserve errno around the call. (The C++ standard requires that
117     // system_error functions not modify errno).
118     const int old_errno = errno;
119     const char *error_message = handle_strerror_r_return(
120         ::strerror_r(ev, buffer, strerror_buff_size), buffer);
121     // If we didn't get any message, print one now.
122     if (!error_message[0]) {
123       std::snprintf(buffer, strerror_buff_size, "Unknown error %d", ev);
124       error_message = buffer;
125     }
126     errno = old_errno;
127     return string(error_message);
128 }
129 #endif
130 } // end namespace
131 #endif
132 
133 string
134 __do_message::message(int ev) const
135 {
136 #if defined(_LIBCPP_HAS_NO_THREADS)
137     return string(::strerror(ev));
138 #else
139     return do_strerror_r(ev);
140 #endif
141 }
142 
143 class _LIBCPP_HIDDEN __generic_error_category
144     : public __do_message
145 {
146 public:
147     virtual const char* name() const noexcept;
148     virtual string message(int ev) const;
149 };
150 
151 const char*
152 __generic_error_category::name() const noexcept
153 {
154     return "generic";
155 }
156 
157 string
158 __generic_error_category::message(int ev) const
159 {
160 #ifdef _LIBCPP_ELAST
161     if (ev > _LIBCPP_ELAST)
162       return string("unspecified generic_category error");
163 #endif // _LIBCPP_ELAST
164     return __do_message::message(ev);
165 }
166 
167 const error_category&
168 generic_category() noexcept
169 {
170     static __generic_error_category s;
171     return s;
172 }
173 
174 class _LIBCPP_HIDDEN __system_error_category
175     : public __do_message
176 {
177 public:
178     virtual const char* name() const noexcept;
179     virtual string message(int ev) const;
180     virtual error_condition default_error_condition(int ev) const noexcept;
181 };
182 
183 const char*
184 __system_error_category::name() const noexcept
185 {
186     return "system";
187 }
188 
189 string
190 __system_error_category::message(int ev) const
191 {
192 #ifdef _LIBCPP_ELAST
193     if (ev > _LIBCPP_ELAST)
194       return string("unspecified system_category error");
195 #endif // _LIBCPP_ELAST
196     return __do_message::message(ev);
197 }
198 
199 error_condition
200 __system_error_category::default_error_condition(int ev) const noexcept
201 {
202 #ifdef _LIBCPP_ELAST
203     if (ev > _LIBCPP_ELAST)
204       return error_condition(ev, system_category());
205 #endif // _LIBCPP_ELAST
206     return error_condition(ev, generic_category());
207 }
208 
209 const error_category&
210 system_category() noexcept
211 {
212     static __system_error_category s;
213     return s;
214 }
215 
216 // error_condition
217 
218 string
219 error_condition::message() const
220 {
221     return __cat_->message(__val_);
222 }
223 
224 // error_code
225 
226 string
227 error_code::message() const
228 {
229     return __cat_->message(__val_);
230 }
231 
232 // system_error
233 
234 string
235 system_error::__init(const error_code& ec, string what_arg)
236 {
237     if (ec)
238     {
239         if (!what_arg.empty())
240             what_arg += ": ";
241         what_arg += ec.message();
242     }
243     return what_arg;
244 }
245 
246 system_error::system_error(error_code ec, const string& what_arg)
247     : runtime_error(__init(ec, what_arg)),
248       __ec_(ec)
249 {
250 }
251 
252 system_error::system_error(error_code ec, const char* what_arg)
253     : runtime_error(__init(ec, what_arg)),
254       __ec_(ec)
255 {
256 }
257 
258 system_error::system_error(error_code ec)
259     : runtime_error(__init(ec, "")),
260       __ec_(ec)
261 {
262 }
263 
264 system_error::system_error(int ev, const error_category& ecat, const string& what_arg)
265     : runtime_error(__init(error_code(ev, ecat), what_arg)),
266       __ec_(error_code(ev, ecat))
267 {
268 }
269 
270 system_error::system_error(int ev, const error_category& ecat, const char* what_arg)
271     : runtime_error(__init(error_code(ev, ecat), what_arg)),
272       __ec_(error_code(ev, ecat))
273 {
274 }
275 
276 system_error::system_error(int ev, const error_category& ecat)
277     : runtime_error(__init(error_code(ev, ecat), "")),
278       __ec_(error_code(ev, ecat))
279 {
280 }
281 
282 system_error::~system_error() noexcept
283 {
284 }
285 
286 void
287 __throw_system_error(int ev, const char* what_arg)
288 {
289 #ifndef _LIBCPP_NO_EXCEPTIONS
290     throw system_error(error_code(ev, system_category()), what_arg);
291 #else
292     (void)ev;
293     (void)what_arg;
294     _VSTD::abort();
295 #endif
296 }
297 
298 _LIBCPP_END_NAMESPACE_STD
299