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 <algorithm>
17 #include <cassert>
18 #include <cstdint>
19
20 using namespace llvm;
21 using namespace llvm::codeview;
22
23 DebugSubsectionRecord::DebugSubsectionRecord() = default;
24
DebugSubsectionRecord(DebugSubsectionKind Kind,BinaryStreamRef Data)25 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
26 BinaryStreamRef Data)
27 : Kind(Kind), Data(Data) {}
28
initialize(BinaryStreamRef Stream,DebugSubsectionRecord & Info)29 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
30 DebugSubsectionRecord &Info) {
31 const DebugSubsectionHeader *Header;
32 BinaryStreamReader Reader(Stream);
33 if (auto EC = Reader.readObject(Header))
34 return EC;
35
36 DebugSubsectionKind Kind =
37 static_cast<DebugSubsectionKind>(uint32_t(Header->Kind));
38 if (auto EC = Reader.readStreamRef(Info.Data, Header->Length))
39 return EC;
40 Info.Kind = Kind;
41 return Error::success();
42 }
43
getRecordLength() const44 uint32_t DebugSubsectionRecord::getRecordLength() const {
45 return sizeof(DebugSubsectionHeader) + Data.getLength();
46 }
47
kind() const48 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
49
getRecordData() const50 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
51
DebugSubsectionRecordBuilder(std::shared_ptr<DebugSubsection> Subsection)52 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
53 std::shared_ptr<DebugSubsection> Subsection)
54 : Subsection(std::move(Subsection)) {}
55
DebugSubsectionRecordBuilder(const DebugSubsectionRecord & Contents)56 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
57 const DebugSubsectionRecord &Contents)
58 : Contents(Contents) {}
59
calculateSerializedLength() const60 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() const {
61 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
62 : Contents.getRecordData().getLength();
63 // The length of the entire subsection is always padded to 4 bytes,
64 // regardless of the container kind.
65 return sizeof(DebugSubsectionHeader) + alignTo(DataSize, 4);
66 }
67
commit(BinaryStreamWriter & Writer,CodeViewContainer Container) const68 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer,
69 CodeViewContainer Container) const {
70 assert(Writer.getOffset() % alignOf(Container) == 0 &&
71 "Debug Subsection not properly aligned");
72
73 DebugSubsectionHeader Header;
74 Header.Kind = uint32_t(Subsection ? Subsection->kind() : Contents.kind());
75 // The value written into the Header's Length field is only padded to the
76 // container's alignment
77 uint32_t DataSize = Subsection ? Subsection->calculateSerializedSize()
78 : Contents.getRecordData().getLength();
79 Header.Length = alignTo(DataSize, alignOf(Container));
80
81 if (auto EC = Writer.writeObject(Header))
82 return EC;
83 if (Subsection) {
84 if (auto EC = Subsection->commit(Writer))
85 return EC;
86 } else {
87 if (auto EC = Writer.writeStreamRef(Contents.getRecordData()))
88 return EC;
89 }
90 if (auto EC = Writer.padToAlignment(4))
91 return EC;
92
93 return Error::success();
94 }
95