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
|
#pragma once
#ifdef __GNUC__
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-parameter"
#endif
//===- StringMapEntry.h - String Hash table map interface -------*- 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
//
//===----------------------------------------------------------------------===//
///
/// \file
/// This file defines the StringMapEntry class - it is intended to be a low
/// dependency implementation detail of StringMap that is more suitable for
/// inclusion in public headers than StringMap.h itself is.
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_ADT_STRINGMAPENTRY_H
#define LLVM_ADT_STRINGMAPENTRY_H
#include "llvm/ADT/None.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/STLFunctionalExtras.h"
namespace llvm {
/// StringMapEntryBase - Shared base class of StringMapEntry instances.
class StringMapEntryBase {
size_t keyLength;
public:
explicit StringMapEntryBase(size_t keyLength) : keyLength(keyLength) {}
size_t getKeyLength() const { return keyLength; }
protected:
/// Helper to tail-allocate \p Key. It'd be nice to generalize this so it
/// could be reused elsewhere, maybe even taking an llvm::function_ref to
/// type-erase the allocator and put it in a source file.
template <typename AllocatorTy>
static void *allocateWithKey(size_t EntrySize, size_t EntryAlign,
StringRef Key, AllocatorTy &Allocator);
};
// Define out-of-line to dissuade inlining.
template <typename AllocatorTy>
void *StringMapEntryBase::allocateWithKey(size_t EntrySize, size_t EntryAlign,
StringRef Key,
AllocatorTy &Allocator) {
size_t KeyLength = Key.size();
// Allocate a new item with space for the string at the end and a null
// terminator.
size_t AllocSize = EntrySize + KeyLength + 1;
void *Allocation = Allocator.Allocate(AllocSize, EntryAlign);
assert(Allocation && "Unhandled out-of-memory");
// Copy the string information.
char *Buffer = reinterpret_cast<char *>(Allocation) + EntrySize;
if (KeyLength > 0)
::memcpy(Buffer, Key.data(), KeyLength);
Buffer[KeyLength] = 0; // Null terminate for convenience of clients.
return Allocation;
}
/// StringMapEntryStorage - Holds the value in a StringMapEntry.
///
/// Factored out into a separate base class to make it easier to specialize.
/// This is primarily intended to support StringSet, which doesn't need a value
/// stored at all.
template <typename ValueTy>
class StringMapEntryStorage : public StringMapEntryBase {
public:
ValueTy second;
explicit StringMapEntryStorage(size_t keyLength)
: StringMapEntryBase(keyLength), second() {}
template <typename... InitTy>
StringMapEntryStorage(size_t keyLength, InitTy &&... initVals)
: StringMapEntryBase(keyLength),
second(std::forward<InitTy>(initVals)...) {}
StringMapEntryStorage(StringMapEntryStorage &e) = delete;
const ValueTy &getValue() const { return second; }
ValueTy &getValue() { return second; }
void setValue(const ValueTy &V) { second = V; }
};
template <> class StringMapEntryStorage<NoneType> : public StringMapEntryBase {
public:
explicit StringMapEntryStorage(size_t keyLength, NoneType = None)
: StringMapEntryBase(keyLength) {}
StringMapEntryStorage(StringMapEntryStorage &entry) = delete;
NoneType getValue() const { return None; }
};
/// StringMapEntry - This is used to represent one value that is inserted into
/// a StringMap. It contains the Value itself and the key: the string length
/// and data.
template <typename ValueTy>
class StringMapEntry final : public StringMapEntryStorage<ValueTy> {
public:
using StringMapEntryStorage<ValueTy>::StringMapEntryStorage;
StringRef getKey() const {
return StringRef(getKeyData(), this->getKeyLength());
}
/// getKeyData - Return the start of the string data that is the key for this
/// value. The string data is always stored immediately after the
/// StringMapEntry object.
const char *getKeyData() const {
return reinterpret_cast<const char *>(this + 1);
}
StringRef first() const {
return StringRef(getKeyData(), this->getKeyLength());
}
/// Create a StringMapEntry for the specified key construct the value using
/// \p InitiVals.
template <typename AllocatorTy, typename... InitTy>
static StringMapEntry *Create(StringRef key, AllocatorTy &allocator,
InitTy &&... initVals) {
return new (StringMapEntryBase::allocateWithKey(
sizeof(StringMapEntry), alignof(StringMapEntry), key, allocator))
StringMapEntry(key.size(), std::forward<InitTy>(initVals)...);
}
/// GetStringMapEntryFromKeyData - Given key data that is known to be embedded
/// into a StringMapEntry, return the StringMapEntry itself.
static StringMapEntry &GetStringMapEntryFromKeyData(const char *keyData) {
char *ptr = const_cast<char *>(keyData) - sizeof(StringMapEntry<ValueTy>);
return *reinterpret_cast<StringMapEntry *>(ptr);
}
/// Destroy - Destroy this StringMapEntry, releasing memory back to the
/// specified allocator.
template <typename AllocatorTy> void Destroy(AllocatorTy &allocator) {
// Free memory referenced by the item.
size_t AllocSize = sizeof(StringMapEntry) + this->getKeyLength() + 1;
this->~StringMapEntry();
allocator.Deallocate(static_cast<void *>(this), AllocSize,
alignof(StringMapEntry));
}
};
} // end namespace llvm
#endif // LLVM_ADT_STRINGMAPENTRY_H
#ifdef __GNUC__
#pragma GCC diagnostic pop
#endif
|
