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 DebugSubsectionRecordBuilder::DebugSubsectionRecordBuilder(
57     const DebugSubsectionRecord &Contents, CodeViewContainer Container)
58     : Contents(Contents), Container(Container) {}
59 
60 uint32_t DebugSubsectionRecordBuilder::calculateSerializedLength() {
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 
68 Error DebugSubsectionRecordBuilder::commit(BinaryStreamWriter &Writer) 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(DataSize, alignOf(Container));
79 
80   if (auto EC = Writer.writeObject(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(Contents.getRecordData()))
87       return EC;
88   }
89   if (auto EC = Writer.padToAlignment(4))
90     return EC;
91 
92   return Error::success();
93 }
94