MPD  0.20.15
Error.hxx
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1 /*
2  * Copyright (C) 2013-2015 Max Kellermann <max.kellermann@gmail.com>
3  *
4  * Redistribution and use in source and binary forms, with or without
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29 
30 #ifndef SYSTEM_ERROR_HXX
31 #define SYSTEM_ERROR_HXX
32 
33 #include "util/StringUtil.hxx"
34 #include "Compiler.h"
35 
36 #include <system_error>
37 #include <utility>
38 
39 #include <stdio.h>
40 
41 template<typename... Args>
42 static inline std::system_error
43 FormatSystemError(std::error_code code, const char *fmt, Args&&... args)
44 {
45  char buffer[1024];
46  snprintf(buffer, sizeof(buffer), fmt, std::forward<Args>(args)...);
47  return std::system_error(code, buffer);
48 }
49 
50 #ifdef _WIN32
51 
52 #include <windows.h>
53 
54 static inline std::system_error
55 MakeLastError(DWORD code, const char *msg)
56 {
57  return std::system_error(std::error_code(code, std::system_category()),
58  msg);
59 }
60 
61 static inline std::system_error
62 MakeLastError(const char *msg)
63 {
64  return MakeLastError(GetLastError(), msg);
65 }
66 
67 template<typename... Args>
68 static inline std::system_error
69 FormatLastError(DWORD code, const char *fmt, Args&&... args)
70 {
71  char buffer[512];
72  const auto end = buffer + sizeof(buffer);
73  size_t length = snprintf(buffer, sizeof(buffer) - 128,
74  fmt, std::forward<Args>(args)...);
75  char *p = buffer + length;
76  *p++ = ':';
77  *p++ = ' ';
78 
79  FormatMessageA(FORMAT_MESSAGE_FROM_SYSTEM |
80  FORMAT_MESSAGE_IGNORE_INSERTS,
81  nullptr, code, 0, p, end - p, nullptr);
82  return MakeLastError(code, buffer);
83 }
84 
85 template<typename... Args>
86 static inline std::system_error
87 FormatLastError(const char *fmt, Args&&... args)
88 {
89  return FormatLastError(GetLastError(), fmt,
90  std::forward<Args>(args)...);
91 }
92 
93 #endif /* _WIN32 */
94 
95 #include <errno.h>
96 #include <string.h>
97 
106 static inline const std::error_category &
108 {
109 #ifdef _WIN32
110  /* on Windows, the generic_category() is used for errno
111  values */
112  return std::generic_category();
113 #else
114  /* on POSIX, system_category() appears to be the best
115  choice */
116  return std::system_category();
117 #endif
118 }
119 
120 static inline std::system_error
121 MakeErrno(int code, const char *msg)
122 {
123  return std::system_error(std::error_code(code, ErrnoCategory()),
124  msg);
125 }
126 
127 static inline std::system_error
128 MakeErrno(const char *msg)
129 {
130  return MakeErrno(errno, msg);
131 }
132 
133 template<typename... Args>
134 static inline std::system_error
135 FormatErrno(int code, const char *fmt, Args&&... args)
136 {
137  char buffer[512];
138  snprintf(buffer, sizeof(buffer),
139  fmt, std::forward<Args>(args)...);
140  return MakeErrno(code, buffer);
141 }
142 
143 template<typename... Args>
144 static inline std::system_error
145 FormatErrno(const char *fmt, Args&&... args)
146 {
147  return FormatErrno(errno, fmt, std::forward<Args>(args)...);
148 }
149 
150 gcc_pure
151 static inline bool
152 IsFileNotFound(const std::system_error &e) noexcept
153 {
154 #ifdef _WIN32
155  return e.code().category() == std::system_category() &&
156  e.code().value() == ERROR_FILE_NOT_FOUND;
157 #else
158  return e.code().category() == ErrnoCategory() &&
159  e.code().value() == ENOENT;
160 #endif
161 }
162 
163 gcc_pure
164 static inline bool
165 IsPathNotFound(const std::system_error &e) noexcept
166 {
167 #ifdef _WIN32
168  return e.code().category() == std::system_category() &&
169  e.code().value() == ERROR_PATH_NOT_FOUND;
170 #else
171  return e.code().category() == ErrnoCategory() &&
172  e.code().value() == ENOTDIR;
173 #endif
174 }
175 
176 gcc_pure
177 static inline bool
178 IsAccessDenied(const std::system_error &e) noexcept
179 {
180 #ifdef _WIN32
181  return e.code().category() == std::system_category() &&
182  e.code().value() == ERROR_ACCESS_DENIED;
183 #else
184  return e.code().category() == ErrnoCategory() &&
185  e.code().value() == EACCES;
186 #endif
187 }
188 
189 #endif
static std::system_error MakeErrno(int code, const char *msg)
Definition: Error.hxx:121
static gcc_pure bool IsFileNotFound(const std::system_error &e) noexcept
Definition: Error.hxx:152
static const std::error_category & ErrnoCategory()
Returns the error_category to be used to wrap errno values.
Definition: Error.hxx:107
static gcc_pure bool IsAccessDenied(const std::system_error &e) noexcept
Definition: Error.hxx:178
static std::system_error FormatErrno(int code, const char *fmt, Args &&... args)
Definition: Error.hxx:135
static gcc_pure bool IsPathNotFound(const std::system_error &e) noexcept
Definition: Error.hxx:165
int e
Definition: Log.hxx:115
#define gcc_pure
Definition: Compiler.h:116
const char * fmt
Definition: Client.hxx:231
static std::system_error FormatSystemError(std::error_code code, const char *fmt, Args &&... args)
Definition: Error.hxx:43