aboutsummaryrefslogtreecommitdiffstats
path: root/src/util/Error.hxx
blob: ab66ae5cb508934e59165211badf611141e73f4d (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/*
 * Copyright (C) 2013 Max Kellermann <max@duempel.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
 * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef ERROR_HXX
#define ERROR_HXX

#include "check.h"
#include "Compiler.h"

#include <string>
#include <utility>

#include <assert.h>

class Domain;

extern const Domain errno_domain;

#ifdef WIN32
/* fuck WIN32! */
#include <windows.h>
#define IgnoreError MPDIgnoreError
#undef GetMessage

/**
 * Domain for GetLastError().
 */
extern const Domain win32_domain;
#endif

/**
 * This class contains information about a runtime error.
 */
class Error {
	const Domain *domain;
	int code;
	std::string message;

public:
	Error():domain(nullptr), code(0) {}

	Error(const Domain &_domain, int _code, const char *_message)
		:domain(&_domain), code(_code), message(_message) {}

	Error(const Domain &_domain, const char *_message)
		:domain(&_domain), code(0), message(_message) {}

	Error(Error &&other)
		:domain(other.domain), code(other.code),
		 message(std::move(other.message)) {}

	~Error();

	Error(const Error &) = delete;
	Error &operator=(const Error &) = delete;

	Error &operator=(Error &&other) {
		domain = other.domain;
		code = other.code;
		std::swap(message, other.message);
		return *this;
	}

	bool IsDefined() const {
		return domain != nullptr;
	}

	void Clear() {
		domain = nullptr;
	}

	const Domain &GetDomain() const {
		assert(IsDefined());

		return *domain;
	}

	bool IsDomain(const Domain &other) const {
		return domain == &other;
	}

	int GetCode() const {
		assert(IsDefined());

		return code;
	}

	const char *GetMessage() const {
		assert(IsDefined());

		return message.c_str();
	}

	void Set(const Error &other) {
		assert(!IsDefined());
		assert(other.IsDefined());

		domain = other.domain;
		code = other.code;
		message = other.message;
	}

	void Set(const Domain &_domain, int _code, const char *_message);

	void Set(const Domain &_domain, const char *_message) {
		Set(_domain, 0, _message);
	}

private:
	void Format2(const Domain &_domain, int _code, const char *fmt, ...);

public:
	template<typename... Args>
	void Format(const Domain &_domain, int _code,
		    const char *fmt, Args&&... args) {
		Format2(_domain, _code, fmt, std::forward<Args>(args)...);
	}

	template<typename... Args>
	void Format(const Domain &_domain, const char *fmt, Args&&... args) {
		Format2(_domain, 0, fmt, std::forward<Args>(args)...);
	}

	void AddPrefix(const char *prefix) {
		message.insert(0, prefix);
	}

	gcc_printf(2,3)
	void FormatPrefix(const char *fmt, ...);

	void SetErrno(int e);
	void SetErrno();
	void SetErrno(int e, const char *prefix);
	void SetErrno(const char *prefix);

	gcc_printf(2,3)
	void FormatErrno(const char *prefix, ...);

	gcc_printf(3,4)
	void FormatErrno(int e, const char *prefix, ...);

#ifdef WIN32
	void SetLastError(DWORD _code, const char *prefix);
	void SetLastError(const char *prefix);

	gcc_printf(3,4)
	void FormatLastError(DWORD code, const char *fmt, ...);

	gcc_printf(2,3)
	void FormatLastError(const char *fmt, ...);
#endif
};

/**
 * Pass a temporary instance of this class to ignore errors.
 */
class IgnoreError final {
	Error error;

public:
	operator Error &() {
		assert(!error.IsDefined());

		return error;
	}
};

#endif