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 <__assert>
10#include <__config>
11#include <__system_error/throw_system_error.h>
12#include <__verbose_abort>
13#include <cerrno>
14#include <cstdio>
15#include <cstdlib>
16#include <cstring>
17#include <optional>
18#include <string.h>
19#include <string>
20#include <system_error>
21
22#include "include/config_elast.h"
23
24#if defined(_LIBCPP_WIN32API)
25# include <windows.h>
26# include <winerror.h>
27#endif
28
29_LIBCPP_BEGIN_NAMESPACE_STD
30
31#if defined(_LIBCPP_WIN32API)
32
33namespace {
34std::optional<errc> __win_err_to_errc(int err) {
35 switch (err) {
36 case ERROR_ACCESS_DENIED:
37 return errc::permission_denied;
38 case ERROR_ALREADY_EXISTS:
39 return errc::file_exists;
40 case ERROR_BAD_NETPATH:
41 return errc::no_such_file_or_directory;
42 case ERROR_BAD_PATHNAME:
43 return errc::no_such_file_or_directory;
44 case ERROR_BAD_UNIT:
45 return errc::no_such_device;
46 case ERROR_BROKEN_PIPE:
47 return errc::broken_pipe;
48 case ERROR_BUFFER_OVERFLOW:
49 return errc::filename_too_long;
50 case ERROR_BUSY:
51 return errc::device_or_resource_busy;
52 case ERROR_BUSY_DRIVE:
53 return errc::device_or_resource_busy;
54 case ERROR_CANNOT_MAKE:
55 return errc::permission_denied;
56 case ERROR_CANTOPEN:
57 return errc::io_error;
58 case ERROR_CANTREAD:
59 return errc::io_error;
60 case ERROR_CANTWRITE:
61 return errc::io_error;
62 case ERROR_CURRENT_DIRECTORY:
63 return errc::permission_denied;
64 case ERROR_DEV_NOT_EXIST:
65 return errc::no_such_device;
66 case ERROR_DEVICE_IN_USE:
67 return errc::device_or_resource_busy;
68 case ERROR_DIR_NOT_EMPTY:
69 return errc::directory_not_empty;
70 case ERROR_DIRECTORY:
71 return errc::invalid_argument;
72 case ERROR_DISK_FULL:
73 return errc::no_space_on_device;
74 case ERROR_FILE_EXISTS:
75 return errc::file_exists;
76 case ERROR_FILE_NOT_FOUND:
77 return errc::no_such_file_or_directory;
78 case ERROR_HANDLE_DISK_FULL:
79 return errc::no_space_on_device;
80 case ERROR_INVALID_ACCESS:
81 return errc::permission_denied;
82 case ERROR_INVALID_DRIVE:
83 return errc::no_such_device;
84 case ERROR_INVALID_FUNCTION:
85 return errc::function_not_supported;
86 case ERROR_INVALID_HANDLE:
87 return errc::invalid_argument;
88 case ERROR_INVALID_NAME:
89 return errc::no_such_file_or_directory;
90 case ERROR_INVALID_PARAMETER:
91 return errc::invalid_argument;
92 case ERROR_LOCK_VIOLATION:
93 return errc::no_lock_available;
94 case ERROR_LOCKED:
95 return errc::no_lock_available;
96 case ERROR_NEGATIVE_SEEK:
97 return errc::invalid_argument;
98 case ERROR_NOACCESS:
99 return errc::permission_denied;
100 case ERROR_NOT_ENOUGH_MEMORY:
101 return errc::not_enough_memory;
102 case ERROR_NOT_READY:
103 return errc::resource_unavailable_try_again;
104 case ERROR_NOT_SAME_DEVICE:
105 return errc::cross_device_link;
106 case ERROR_NOT_SUPPORTED:
107 return errc::not_supported;
108 case ERROR_OPEN_FAILED:
109 return errc::io_error;
110 case ERROR_OPEN_FILES:
111 return errc::device_or_resource_busy;
112 case ERROR_OPERATION_ABORTED:
113 return errc::operation_canceled;
114 case ERROR_OUTOFMEMORY:
115 return errc::not_enough_memory;
116 case ERROR_PATH_NOT_FOUND:
117 return errc::no_such_file_or_directory;
118 case ERROR_READ_FAULT:
119 return errc::io_error;
120 case ERROR_REPARSE_TAG_INVALID:
121 return errc::invalid_argument;
122 case ERROR_RETRY:
123 return errc::resource_unavailable_try_again;
124 case ERROR_SEEK:
125 return errc::io_error;
126 case ERROR_SHARING_VIOLATION:
127 return errc::permission_denied;
128 case ERROR_TOO_MANY_OPEN_FILES:
129 return errc::too_many_files_open;
130 case ERROR_WRITE_FAULT:
131 return errc::io_error;
132 case ERROR_WRITE_PROTECT:
133 return errc::permission_denied;
134 default:
135 return {};
136 }
137}
138} // namespace
139#endif
140
141namespace {
142#if _LIBCPP_HAS_THREADS
143
144// GLIBC also uses 1024 as the maximum buffer size internally.
145constexpr size_t strerror_buff_size = 1024;
146
147string do_strerror_r(int ev);
148
149# if defined(_LIBCPP_MSVCRT_LIKE)
150string do_strerror_r(int ev) {
151 char buffer[strerror_buff_size];
152 if (::strerror_s(buffer, strerror_buff_size, ev) == 0)
153 return string(buffer);
154 std::snprintf(buffer, strerror_buff_size, "unknown error %d", ev);
155 return string(buffer);
156}
157# else
158
159// Only one of the two following functions will be used, depending on
160// the return type of strerror_r:
161
162// For the GNU variant, a char* return value:
163__attribute__((unused)) const char* handle_strerror_r_return(char* strerror_return, char* buffer) {
164 // GNU always returns a string pointer in its return value. The
165 // string might point to either the input buffer, or a static
166 // buffer, but we don't care which.
167 return strerror_return;
168}
169
170// For the POSIX variant: an int return value.
171__attribute__((unused)) const char* handle_strerror_r_return(int strerror_return, char* buffer) {
172 // The POSIX variant either:
173 // - fills in the provided buffer and returns 0
174 // - returns a positive error value, or
175 // - returns -1 and fills in errno with an error value.
176 if (strerror_return == 0)
177 return buffer;
178
179 // Only handle EINVAL. Other errors abort.
180 int new_errno = strerror_return == -1 ? errno : strerror_return;
181 if (new_errno == EINVAL)
182 return "";
183
184 _LIBCPP_ASSERT_INTERNAL(new_errno == ERANGE, "unexpected error from ::strerror_r");
185 // FIXME maybe? 'strerror_buff_size' is likely to exceed the
186 // maximum error size so ERANGE shouldn't be returned.
187 std::abort();
188}
189
190// This function handles both GNU and POSIX variants, dispatching to
191// one of the two above functions.
192string do_strerror_r(int ev) {
193 char buffer[strerror_buff_size];
194 // Preserve errno around the call. (The C++ standard requires that
195 // system_error functions not modify errno).
196 const int old_errno = errno;
197 const char* error_message = handle_strerror_r_return(strerror_return: ::strerror_r(errnum: ev, buf: buffer, buflen: strerror_buff_size), buffer);
198 // If we didn't get any message, print one now.
199 if (!error_message[0]) {
200 std::snprintf(s: buffer, maxlen: strerror_buff_size, format: "Unknown error %d", ev);
201 error_message = buffer;
202 }
203 errno = old_errno;
204 return string(error_message);
205}
206# endif
207
208#endif // _LIBCPP_HAS_THREADS
209
210string make_error_str(const error_code& ec, string what_arg) {
211 if (ec) {
212 if (!what_arg.empty()) {
213 what_arg += ": ";
214 }
215 what_arg += ec.message();
216 }
217 return what_arg;
218}
219
220string make_error_str(const error_code& ec) {
221 if (ec) {
222 return ec.message();
223 }
224 return string();
225}
226} // namespace
227
228string __do_message::message(int ev) const {
229#if !_LIBCPP_HAS_THREADS
230 return string(::strerror(ev));
231#else
232 return do_strerror_r(ev);
233#endif
234}
235
236class _LIBCPP_HIDDEN __generic_error_category : public __do_message {
237public:
238 virtual const char* name() const noexcept;
239 virtual string message(int ev) const;
240};
241
242const char* __generic_error_category::name() const noexcept { return "generic"; }
243
244string __generic_error_category::message(int ev) const {
245#ifdef _LIBCPP_ELAST
246 if (ev > _LIBCPP_ELAST)
247 return string("unspecified generic_category error");
248#endif // _LIBCPP_ELAST
249 return __do_message::message(ev);
250}
251
252const error_category& generic_category() noexcept {
253 union AvoidDestroyingGenericCategory {
254 __generic_error_category generic_error_category;
255 constexpr explicit AvoidDestroyingGenericCategory() : generic_error_category() {}
256 ~AvoidDestroyingGenericCategory() {}
257 };
258 constinit static AvoidDestroyingGenericCategory helper;
259 return helper.generic_error_category;
260}
261
262class _LIBCPP_HIDDEN __system_error_category : public __do_message {
263public:
264 virtual const char* name() const noexcept;
265 virtual string message(int ev) const;
266 virtual error_condition default_error_condition(int ev) const noexcept;
267};
268
269const char* __system_error_category::name() const noexcept { return "system"; }
270
271string __system_error_category::message(int ev) const {
272#ifdef _LIBCPP_WIN32API
273 std::string result;
274 char* str = nullptr;
275 unsigned long num_chars = ::FormatMessageA(
276 FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
277 nullptr,
278 ev,
279 0,
280 reinterpret_cast<char*>(&str),
281 0,
282 nullptr);
283 auto is_whitespace = [](char ch) { return ch == '\n' || ch == '\r' || ch == ' '; };
284 while (num_chars > 0 && is_whitespace(str[num_chars - 1]))
285 --num_chars;
286
287 if (num_chars)
288 result = std::string(str, num_chars);
289 else
290 result = "Unknown error";
291
292 LocalFree(str);
293 return result;
294#else
295# ifdef _LIBCPP_ELAST
296 if (ev > _LIBCPP_ELAST)
297 return string("unspecified system_category error");
298# endif // _LIBCPP_ELAST
299 return __do_message::message(ev);
300#endif
301}
302
303error_condition __system_error_category::default_error_condition(int ev) const noexcept {
304#ifdef _LIBCPP_WIN32API
305 // Remap windows error codes to generic error codes if possible.
306 if (ev == 0)
307 return error_condition(0, generic_category());
308 if (auto maybe_errc = __win_err_to_errc(ev))
309 return error_condition(static_cast<int>(*maybe_errc), generic_category());
310 return error_condition(ev, system_category());
311#else
312# ifdef _LIBCPP_ELAST
313 if (ev > _LIBCPP_ELAST)
314 return error_condition(ev, system_category());
315# endif // _LIBCPP_ELAST
316 return error_condition(ev, generic_category());
317#endif
318}
319
320const error_category& system_category() noexcept {
321 union AvoidDestroyingSystemCategory {
322 __system_error_category system_error_category;
323 constexpr explicit AvoidDestroyingSystemCategory() : system_error_category() {}
324 ~AvoidDestroyingSystemCategory() {}
325 };
326 constinit static AvoidDestroyingSystemCategory helper;
327 return helper.system_error_category;
328}
329
330// error_condition
331
332string error_condition::message() const { return __cat_->message(ev: __val_); }
333
334// error_code
335
336string error_code::message() const { return __cat_->message(ev: __val_); }
337
338// system_error
339
340system_error::system_error(error_code ec, const string& what_arg)
341 : runtime_error(make_error_str(ec, what_arg)), __ec_(ec) {}
342
343system_error::system_error(error_code ec, const char* what_arg)
344 : runtime_error(make_error_str(ec, what_arg)), __ec_(ec) {}
345
346system_error::system_error(error_code ec) : runtime_error(make_error_str(ec)), __ec_(ec) {}
347
348system_error::system_error(int ev, const error_category& ecat, const string& what_arg)
349 : runtime_error(make_error_str(ec: error_code(ev, ecat), what_arg)), __ec_(error_code(ev, ecat)) {}
350
351system_error::system_error(int ev, const error_category& ecat, const char* what_arg)
352 : runtime_error(make_error_str(ec: error_code(ev, ecat), what_arg)), __ec_(error_code(ev, ecat)) {}
353
354system_error::system_error(int ev, const error_category& ecat)
355 : runtime_error(make_error_str(ec: error_code(ev, ecat))), __ec_(error_code(ev, ecat)) {}
356
357system_error::~system_error() noexcept {}
358
359void __throw_system_error(int ev, const char* what_arg) {
360#if _LIBCPP_HAS_EXCEPTIONS
361 std::__throw_system_error(ec: error_code(ev, generic_category()), what_arg: what_arg);
362#else
363 // The above could also handle the no-exception case, but for size, avoid referencing system_category() unnecessarily.
364 _LIBCPP_VERBOSE_ABORT(
365 "system_error was thrown in -fno-exceptions mode with error %i and message \"%s\"", ev, what_arg);
366#endif
367}
368
369_LIBCPP_END_NAMESPACE_STD
370