forked from SerenityOS/serenity
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Error.h
129 lines (104 loc) Β· 3.24 KB
/
Error.h
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
/*
* Copyright (c) 2021, Andreas Kling <[email protected]>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/StringView.h>
#include <AK/Try.h>
#include <AK/Variant.h>
#if defined(AK_OS_SERENITY) && defined(KERNEL)
# include <LibC/errno_codes.h>
#else
# include <errno.h>
# include <string.h>
#endif
namespace AK {
class Error {
public:
static Error from_errno(int code) { return Error(code); }
static Error from_syscall(StringView syscall_name, int rc) { return Error(syscall_name, rc); }
static Error from_string_view(StringView string_literal) { return Error(string_literal); }
// NOTE: Prefer `from_string_literal` when directly typing out an error message:
//
// return Error::from_string_literal("Class: Some failure");
//
// If you need to return a static string based on a dynamic condition (like
// picking an error from an array), then prefer `from_string_view` instead.
template<size_t N>
ALWAYS_INLINE static Error from_string_literal(char const (&string_literal)[N])
{
return from_string_view(StringView { string_literal, N - 1 });
}
bool operator==(Error const& other) const
{
return m_code == other.m_code && m_string_literal == other.m_string_literal && m_syscall == other.m_syscall;
}
bool is_errno() const { return m_code != 0; }
bool is_syscall() const { return m_syscall; }
int code() const { return m_code; }
StringView string_literal() const { return m_string_literal; }
protected:
Error(int code)
: m_code(code)
{
}
private:
Error(StringView string_literal)
: m_string_literal(string_literal)
{
}
Error(StringView syscall_name, int rc)
: m_code(-rc)
, m_string_literal(syscall_name)
, m_syscall(true)
{
}
int m_code { 0 };
StringView m_string_literal;
bool m_syscall { false };
};
template<typename T, typename ErrorType>
class [[nodiscard]] ErrorOr {
public:
ErrorOr() requires(IsSame<T, Empty>)
: m_value_or_error(Empty {})
{
}
template<typename U>
ALWAYS_INLINE ErrorOr(U&& value) requires(!IsSame<RemoveCVReference<U>, ErrorOr<T, ErrorType>>)
: m_value_or_error(forward<U>(value))
{
}
#ifdef AK_OS_SERENITY
ErrorOr(ErrnoCode code)
: m_value_or_error(Error::from_errno(code))
{
}
#endif
T& value()
{
return m_value_or_error.template get<T>();
}
T const& value() const { return m_value_or_error.template get<T>(); }
ErrorType& error() { return m_value_or_error.template get<ErrorType>(); }
ErrorType const& error() const { return m_value_or_error.template get<ErrorType>(); }
bool is_error() const { return m_value_or_error.template has<ErrorType>(); }
T release_value() { return move(value()); }
ErrorType release_error() { return move(error()); }
T release_value_but_fixme_should_propagate_errors()
{
VERIFY(!is_error());
return release_value();
}
private:
Variant<T, ErrorType> m_value_or_error;
};
template<typename ErrorType>
class [[nodiscard]] ErrorOr<void, ErrorType> : public ErrorOr<Empty, ErrorType> {
public:
using ErrorOr<Empty, ErrorType>::ErrorOr;
};
}
using AK::Error;
using AK::ErrorOr;