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
|
//===--- BCReadingExtras.h - Useful helpers for bitcode reading -*- C++ -*-===//
//
// This source file is part of the Swift.org open source project
//
// Copyright (c) 2014 - 2017 Apple Inc. and the Swift project authors
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
// See https://swift.org/CONTRIBUTORS.txt for the list of Swift project authors
//
//===----------------------------------------------------------------------===//
#ifndef SWIFT_SERIALIZATION_BCREADINGEXTRAS_H
#define SWIFT_SERIALIZATION_BCREADINGEXTRAS_H
#include "llvm/Bitstream/BitstreamReader.h"
namespace swift {
namespace serialization {
/// Saves and restores a BitstreamCursor's bit offset in its stream.
class BCOffsetRAII {
llvm::BitstreamCursor *Cursor;
decltype(Cursor->GetCurrentBitNo()) Offset;
public:
explicit BCOffsetRAII(llvm::BitstreamCursor &cursor)
: Cursor(&cursor), Offset(cursor.GetCurrentBitNo()) {}
void reset() {
if (Cursor)
Offset = Cursor->GetCurrentBitNo();
}
void cancel() {
Cursor = nullptr;
}
~BCOffsetRAII() {
if (Cursor)
cantFail(Cursor->JumpToBit(Offset),
"BCOffsetRAII must be able to go back");
}
};
} // end namespace serialization
} // end namespace swift
static constexpr const auto AF_DontPopBlockAtEnd =
llvm::BitstreamCursor::AF_DontPopBlockAtEnd;
#endif
|
