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
|
//===- FormatVariadicDetails.h - Helpers for FormatVariadic.h ----*- C++-*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_FORMATVARIADICDETAILS_H
#define LLVM_SUPPORT_FORMATVARIADICDETAILS_H
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/raw_ostream.h"
#include <type_traits>
namespace llvm {
template <typename T, typename Enable = void> struct format_provider {};
class Error;
namespace detail {
class format_adapter {
virtual void anchor();
protected:
virtual ~format_adapter() {}
public:
virtual void format(raw_ostream &S, StringRef Options) = 0;
};
template <typename T> class provider_format_adapter : public format_adapter {
T Item;
public:
explicit provider_format_adapter(T &&Item) : Item(std::forward<T>(Item)) {}
void format(llvm::raw_ostream &S, StringRef Options) override {
format_provider<std::decay_t<T>>::format(Item, S, Options);
}
};
template <typename T>
class stream_operator_format_adapter : public format_adapter {
T Item;
public:
explicit stream_operator_format_adapter(T &&Item)
: Item(std::forward<T>(Item)) {}
void format(llvm::raw_ostream &S, StringRef) override { S << Item; }
};
template <typename T> class missing_format_adapter;
// Test if format_provider<T> is defined on T and contains a member function
// with the signature:
// static void format(const T&, raw_stream &, StringRef);
//
template <class T> class has_FormatProvider {
public:
using Decayed = std::decay_t<T>;
typedef void (*Signature_format)(const Decayed &, llvm::raw_ostream &,
StringRef);
template <typename U>
static char test(SameType<Signature_format, &U::format> *);
template <typename U> static double test(...);
static bool const value =
(sizeof(test<llvm::format_provider<Decayed>>(nullptr)) == 1);
};
// Test if raw_ostream& << T -> raw_ostream& is findable via ADL.
template <class T> class has_StreamOperator {
public:
using ConstRefT = const std::decay_t<T> &;
template <typename U>
static char test(
std::enable_if_t<std::is_same<decltype(std::declval<llvm::raw_ostream &>()
<< std::declval<U>()),
llvm::raw_ostream &>::value,
int *>);
template <typename U> static double test(...);
static bool const value = (sizeof(test<ConstRefT>(nullptr)) == 1);
};
// Simple template that decides whether a type T should use the member-function
// based format() invocation.
template <typename T>
struct uses_format_member
: public std::integral_constant<
bool,
std::is_base_of<format_adapter, std::remove_reference_t<T>>::value> {
};
// Simple template that decides whether a type T should use the format_provider
// based format() invocation. The member function takes priority, so this test
// will only be true if there is not ALSO a format member.
template <typename T>
struct uses_format_provider
: public std::integral_constant<
bool, !uses_format_member<T>::value && has_FormatProvider<T>::value> {
};
// Simple template that decides whether a type T should use the operator<<
// based format() invocation. This takes last priority.
template <typename T>
struct uses_stream_operator
: public std::integral_constant<bool, !uses_format_member<T>::value &&
!uses_format_provider<T>::value &&
has_StreamOperator<T>::value> {};
// Simple template that decides whether a type T has neither a member-function
// nor format_provider based implementation that it can use. Mostly used so
// that the compiler spits out a nice diagnostic when a type with no format
// implementation can be located.
template <typename T>
struct uses_missing_provider
: public std::integral_constant<bool, !uses_format_member<T>::value &&
!uses_format_provider<T>::value &&
!uses_stream_operator<T>::value> {
};
template <typename T>
std::enable_if_t<uses_format_member<T>::value, T>
build_format_adapter(T &&Item) {
return std::forward<T>(Item);
}
template <typename T>
std::enable_if_t<uses_format_provider<T>::value, provider_format_adapter<T>>
build_format_adapter(T &&Item) {
return provider_format_adapter<T>(std::forward<T>(Item));
}
template <typename T>
std::enable_if_t<uses_stream_operator<T>::value,
stream_operator_format_adapter<T>>
build_format_adapter(T &&Item) {
// If the caller passed an Error by value, then stream_operator_format_adapter
// would be responsible for consuming it.
// Make the caller opt into this by calling fmt_consume().
static_assert(
!std::is_same<llvm::Error, std::remove_cv_t<T>>::value,
"llvm::Error-by-value must be wrapped in fmt_consume() for formatv");
return stream_operator_format_adapter<T>(std::forward<T>(Item));
}
template <typename T>
std::enable_if_t<uses_missing_provider<T>::value, missing_format_adapter<T>>
build_format_adapter(T &&) {
return missing_format_adapter<T>();
}
}
}
#endif
|
