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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
|
#pragma once
/**
* @file
*
* @brief This file defines two main structs/classes used in nix error handling.
*
* ErrorInfo provides a standard payload of error information, with conversion to string
* happening in the logger rather than at the call site.
*
* BaseError is the ancestor of nix specific exceptions (and Interrupted), and contains
* an ErrorInfo.
*
* ErrorInfo structs are sent to the logger as part of an exception, or directly with the
* logError or logWarning macros.
* See libutil/tests/logging.cc for usage examples.
*/
#include "suggestions.hh"
#include "ref.hh"
#include "types.hh"
#include "fmt.hh"
#include <cstring>
#include <list>
#include <memory>
#include <map>
#include <optional>
#include <compare>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
/* Before 4.7, gcc's std::exception uses empty throw() specifiers for
* its (virtual) destructor and what() in c++11 mode, in violation of spec
*/
#ifdef __GNUC__
#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
#define EXCEPTION_NEEDS_THROW_SPEC
#endif
#endif
namespace nix {
typedef enum {
lvlError = 0,
lvlWarn,
lvlNotice,
lvlInfo,
lvlTalkative,
lvlChatty,
lvlDebug,
lvlVomit
} Verbosity;
/**
* The lines of code surrounding an error.
*/
struct LinesOfCode {
std::optional<std::string> prevLineOfCode;
std::optional<std::string> errLineOfCode;
std::optional<std::string> nextLineOfCode;
};
struct Pos;
void printCodeLines(std::ostream & out,
const std::string & prefix,
const Pos & errPos,
const LinesOfCode & loc);
struct Trace {
std::shared_ptr<Pos> pos;
hintformat hint;
bool frame;
};
inline bool operator<(const Trace& lhs, const Trace& rhs);
inline bool operator> (const Trace& lhs, const Trace& rhs);
inline bool operator<=(const Trace& lhs, const Trace& rhs);
inline bool operator>=(const Trace& lhs, const Trace& rhs);
struct ErrorInfo {
Verbosity level;
hintformat msg;
std::shared_ptr<Pos> pos;
std::list<Trace> traces;
/**
* Exit status.
*/
unsigned int status = 1;
Suggestions suggestions;
static std::optional<std::string> programName;
};
std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool showTrace);
/**
* BaseError should generally not be caught, as it has Interrupted as
* a subclass. Catch Error instead.
*/
class BaseError : public std::exception
{
protected:
mutable ErrorInfo err;
/**
* Cached formatted contents of `err.msg`.
*/
mutable std::optional<std::string> what_;
/**
* Format `err.msg` and set `what_` to the resulting value.
*/
const std::string & calcWhat() const;
public:
BaseError(const BaseError &) = default;
template<typename... Args>
BaseError(unsigned int status, const Args & ... args)
: err { .level = lvlError, .msg = hintfmt(args...), .status = status }
{ }
template<typename... Args>
explicit BaseError(const std::string & fs, const Args & ... args)
: err { .level = lvlError, .msg = hintfmt(fs, args...) }
{ }
template<typename... Args>
BaseError(const Suggestions & sug, const Args & ... args)
: err { .level = lvlError, .msg = hintfmt(args...), .suggestions = sug }
{ }
BaseError(hintformat hint)
: err { .level = lvlError, .msg = hint }
{ }
BaseError(ErrorInfo && e)
: err(std::move(e))
{ }
BaseError(const ErrorInfo & e)
: err(e)
{ }
#ifdef EXCEPTION_NEEDS_THROW_SPEC
~BaseError() throw () { };
const char * what() const throw () { return calcWhat().c_str(); }
#else
const char * what() const noexcept override { return calcWhat().c_str(); }
#endif
const std::string & msg() const { return calcWhat(); }
const ErrorInfo & info() const { calcWhat(); return err; }
void withExitStatus(unsigned int status)
{
err.status = status;
}
void atPos(std::shared_ptr<Pos> pos) {
err.pos = pos;
}
void pushTrace(Trace trace)
{
err.traces.push_front(trace);
}
template<typename... Args>
void addTrace(std::shared_ptr<Pos> && e, std::string_view fs, const Args & ... args)
{
addTrace(std::move(e), hintfmt(std::string(fs), args...));
}
void addTrace(std::shared_ptr<Pos> && e, hintformat hint, bool frame = false);
bool hasTrace() const { return !err.traces.empty(); }
const ErrorInfo & info() { return err; };
};
#define MakeError(newClass, superClass) \
class newClass : public superClass \
{ \
public: \
using superClass::superClass; \
}
MakeError(Error, BaseError);
MakeError(UsageError, Error);
MakeError(UnimplementedError, Error);
class SysError : public Error
{
public:
int errNo;
template<typename... Args>
SysError(int errNo_, const Args & ... args)
: Error("")
{
errNo = errNo_;
auto hf = hintfmt(args...);
err.msg = hintfmt("%1%: %2%", normaltxt(hf.str()), strerror(errNo));
}
template<typename... Args>
SysError(const Args & ... args)
: SysError(errno, args ...)
{
}
};
/** Throw an exception for the purpose of checking that exception handling works; see 'initLibUtil()'.
*/
void throwExceptionSelfCheck();
}
|
