1 //===- DebugSubsectionRecord.cpp -----------------------------*- C++-*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 
10 #include "llvm/DebugInfo/CodeView/DebugSubsectionRecord.h"
11 #include "llvm/DebugInfo/CodeView/DebugSubsection.h"
12 
13 #include "llvm/Support/BinaryStreamReader.h"
14 
15 using namespace llvm;
16 using namespace llvm::codeview;
17 
18 DebugSubsectionRecord::DebugSubsectionRecord()
19     : Container(CodeViewContainer::ObjectFile),
20       Kind(DebugSubsectionKind::None) {}
21 
22 DebugSubsectionRecord::DebugSubsectionRecord(DebugSubsectionKind Kind,
23                                              BinaryStreamRef Data,
24                                              CodeViewContainer Container)
25     : Container(Container), Kind(Kind), Data(Data) {}
26 
27 Error DebugSubsectionRecord::initialize(BinaryStreamRef Stream,
28                                         DebugSubsectionRecord &Info,
29                                         CodeViewContainer Container) {
30   const DebugSubsectionHeader *Header;
31   BinaryStreamReader Reader(Stream);
32   if (auto EC = Reader.readObject(Header))
33     return EC;
34 
35   DebugSubsectionKind Kind =
36       static_cast<DebugSubsectionKind>(uint32_t(Header->Kind));
37   if (auto EC = Reader.readStreamRef(Info.Data, Header->Length))
38     return EC;
39   Info.Container = Container;
40   Info.Kind = Kind;
41   return Error::success();
42 }
43 
44 uint32_t DebugSubsectionRecord::getRecordLength() const {
45   return sizeof(DebugSubsectionHeader) + Data.getLength();
46 }
47 
48 DebugSubsectionKind DebugSubsectionRecord::kind() const { return Kind; }
49 
50 BinaryStreamRef DebugSubsectionRecord::getRecordData() const { return Data; }
51 
52 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
53     std::shared_ptr<DebugSubsection> Subsection, CodeViewContainer Container)
54     : Subsection(std::move(Subsection)), Container(Container) {}
55 
56 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
57   // The length of the entire subsection is always padded to 4 bytes, regardless
58   // of the container kind.
59   uint32_t Size = sizeof(DebugSubsectionHeader) +
60                   alignTo(Subsection->calculateSerializedSize(), 4);
61   return Size;
62 }
63 
64 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) const {
65   assert(Writer.getOffset() % alignOf(Container) == 0 &&
66          "Debug Subsection not properly aligned");
67 
68   DebugSubsectionHeader Header;
69   Header.Kind = uint32_t(Subsection->kind());
70   // The value written into the Header's Length field is only padded to the
71   // container's alignment
72   Header.Length =
73       alignTo(Subsection->calculateSerializedSize(), alignOf(Container));
74 
75   if (auto EC = Writer.writeObject(Header))
76     return EC;
77   if (auto EC = Subsection->commit(Writer))
78     return EC;
79   if (auto EC = Writer.padToAlignment(4))
80     return EC;
81 
82   return Error::success();
83 }
84