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
|
#pragma once
#include "ref.hh"
#include <string>
#include <list>
#include <set>
#include <memory>
#include <boost/format.hpp>
/* 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 {
/* Inherit some names from other namespaces for convenience. */
using std::string;
using std::list;
using std::set;
using std::vector;
using boost::format;
struct FormatOrString
{
string s;
FormatOrString(const string & s) : s(s) { };
FormatOrString(const format & f) : s(f.str()) { };
FormatOrString(const char * s) : s(s) { };
};
/* A helper for formatting strings. ‘fmt(format, a_0, ..., a_n)’ is
equivalent to ‘boost::format(format) % a_0 % ... %
... a_n’. However, ‘fmt(s)’ is equivalent to ‘s’ (so no %-expansion
takes place). */
inline void formatHelper(boost::format & f)
{
}
template<typename T, typename... Args>
inline void formatHelper(boost::format & f, T x, Args... args)
{
formatHelper(f % x, args...);
}
inline std::string fmt(const std::string & s)
{
return s;
}
inline std::string fmt(const char * s)
{
return s;
}
inline std::string fmt(const FormatOrString & fs)
{
return fs.s;
}
template<typename... Args>
inline std::string fmt(const std::string & fs, Args... args)
{
boost::format f(fs);
formatHelper(f, args...);
return f.str();
}
/* BaseError should generally not be caught, as it has Interrupted as
a subclass. Catch Error instead. */
class BaseError : public std::exception
{
protected:
string prefix_; // used for location traces etc.
string err;
public:
unsigned int status = 1; // exit status
template<typename... Args>
BaseError(unsigned int status, Args... args)
: err(fmt(args...))
, status(status)
{
}
template<typename... Args>
BaseError(Args... args)
: err(fmt(args...))
{
}
#ifdef EXCEPTION_NEEDS_THROW_SPEC
~BaseError() throw () { };
const char * what() const throw () { return err.c_str(); }
#else
const char * what() const noexcept { return err.c_str(); }
#endif
const string & msg() const { return err; }
const string & prefix() const { return prefix_; }
BaseError & addPrefix(const FormatOrString & fs);
};
#define MakeError(newClass, superClass) \
class newClass : public superClass \
{ \
public: \
using superClass::superClass; \
};
MakeError(Error, BaseError)
class SysError : public Error
{
public:
int errNo;
template<typename... Args>
SysError(Args... args)
: Error(addErrno(fmt(args...)))
{ }
private:
std::string addErrno(const std::string & s);
};
typedef list<string> Strings;
typedef set<string> StringSet;
/* Paths are just strings. */
typedef string Path;
typedef list<Path> Paths;
typedef set<Path> PathSet;
}
|
