1//===- DebugSubsectionRecord.cpp ------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9#include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
10#include "llvm/DebugInfo/CodeView/CodeView.h"
11#include "llvm/DebugInfo/CodeView/DebugSubsection.h"
12#include "llvm/Support/BinaryStreamReader.h"
13#include "llvm/Support/BinaryStreamWriter.h"
14#include "llvm/Support/Error.h"
15#include "llvm/Support/MathExtras.h"
16#include <cassert>
17#include <cstdint>
18
19using namespace llvm;
20using namespace llvm::codeview;
21
22DebugSubsectionRecord::DebugSubsectionRecord() = default;
23
24DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
25 BinaryStreamRef Data)
26 : Kind(Kind), Data(Data) {}
27
28Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
29 DebugSubsectionRecord &Info) {
30 const DebugSubsectionHeader *Header;
31 BinaryStreamReader Reader(Stream);
32 if (auto EC = Reader.readObject(Dest&: Header))
33 return EC;
34
35 DebugSubsectionKind Kind =
36 static_cast<DebugSubsectionKind>(uint32_t(Header->Kind));
37 if (auto EC = Reader.readStreamRef(Ref&: Info.Data, Length: Header->Length))
38 return EC;
39 Info.Kind = Kind;
40 return Error::success();
41}
42
43uint32_t DebugSubsectionRecord::getRecordLength() const {
44 return sizeof(DebugSubsectionHeader) + Data.getLength();
45}
46
47DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
48
49BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
50
51DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
52 std::shared_ptr<DebugSubsection> Subsection)
53 : Subsection(std::move(Subsection)) {}
54
55DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
56 const DebugSubsectionRecord &Contents)
57 : Contents(Contents) {}
58
59uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() const {
60 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
61 : Contents.getRecordData().getLength();
62 // The length of the entire subsection is always padded to 4 bytes,
63 // regardless of the container kind.
64 return sizeof(DebugSubsectionHeader) + alignTo(Value: DataSize, Align: 4);
65}
66
67Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer,
68 CodeViewContainer Container) const {
69 assert(Writer.getOffset() % alignOf(Container) == 0 &&
70 "Debug Subsection not properly aligned");
71
72 DebugSubsectionHeader Header;
73 Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind());
74 // The value written into the Header's Length field is only padded to the
75 // container's alignment
76 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
77 : Contents.getRecordData().getLength();
78 Header.Length = alignTo(Value: DataSize, Align: alignOf(Container));
79
80 if (auto EC = Writer.writeObject(Obj: Header))
81 return EC;
82 if (Subsection) {
83 if (auto EC = Subsection->commit(Writer))
84 return EC;
85 } else {
86 if (auto EC = Writer.writeStreamRef(Ref: Contents.getRecordData()))
87 return EC;
88 }
89 if (auto EC = Writer.padToAlignment(Align: 4))
90 return EC;
91
92 return Error::success();
93}
94